What is Giftedness? :: Biology Essays Research Papers

Maria, a friend of my mothers, at a time complained to our family about the public school system in Florida. She claimed Peter, her six-year-old child, is extremely innate(predicate) and not only could he play the violin and chess, hardly he could also read upper-level books. Despite all this, he did not make it into the gifted curriculum at school - a program that she believed he rightfully deserved to be a member of. why was she so upset over the outcome, and what deciding factors do people come across that could lead to the child being selected against an accelerated program? In new years at that place hire been a strong resurgence in the study of giftedness in children- many people have attempted to rationalize the phenomena and why there are so few who are invest with the asset. Research has promised new insights on the identification and subsequent proper discussion for gifted individuals. What factors may influence innate talent in certain(prenominal) people - is i t based on genetic, neurophysiological, or psychological factors? In my oddment makeup, I had discussed the various research projects that have attempted to link giftedness to the head - with interesting results that are still yet to be firmly established. This paper will attempt to show how giftedness as a concept has been misrepresent in general, and how it presently cannot be utilize to directly identify individuals barely can be used as an inference tool only. Nevertheless, determination a basis or correlates for the concept is whateverthing society finds important, because of the believed implications it will have for the gifted children in the future. The age-old issue of what makes giftedness has been debated in the academic orbit for many years. Before recent studies, it was widely believed that giftedness merely relates to the intellect only. straightway many scientists believe that the term correlates not only to intelligence but also to creativity, memory, motiva tion, physical dexterity, and aesthetic sensitivity (1). It is without doubt that there is some basis to the fact that a few people learn straightaway than others, or have an accelerated sensitivity to art, music, or mathematics. But is this receivable to an innate ability of the particular person? Or are there several complex factors involved not involved with the individuals body? Is sense datum a unified brain phenomena, or is it a term used to describe different phenomena in different persons? Many believe that giftedness is repayable to some innate process independent, for example, from the environment the individual is raised in.

Explain how each of the 4 settings has a profound effect on the charact

Explain how individually of the 4 settings has a incomprehensible effect on the characters in the wise. apiece of the 4 settings in the figment persuasion by Jane Austen holds a difficult effect andQuestion explain how each of the 4 settings has a profound effect onthe characters in the novel.Each of the 4 settings in the novel persuasion by Jane Austen holds aprofound effect and significance on the characters of the novel.Firstly we have kellynch hall, the inhabitants and avowers of kellynchhall are the Elliot family, Sir Walter Elliot and his two daughters,Elizabeth and Anne Elliot. Kellynch in the novel is described as arather exquisite setting, Mrs Croft was impressed with thefurnishings. Lawns and heyday gardens, from the owners personalities,obsessions with appearance, desire to have a high social stance and flamboyant outlook on life we can only gather that kellynch is arather exquisite site.The setting heavily reflects on the characters of kellynch hall- SirWalter Ell iot, a spell for whom vanity was the beginning and end ofhis character. His favourite al-Quran, the reader is told, is theBaronetage, a book which holds record of the most important familiesin England, and which, most importantly records Sir Walters ownpersonal history, And Elizabeth, who is beautiful, yet vain like herfather and Anne, who has a sweet of character, merely is oftenoverlooked by her family. Kellynch appears to be more whence what seemson the surface, lavish furniture and ornaments impressivefurnishings the ornaments and furnishings almost to cover up for anunderlying truth.As kellynch is an old building there are incontestable to be a few cracks andbroken aspects of kellynch hall. Similarly the truth of the ... ...th and wealth, buton ones accomplishments, manners, and interests.In Somersetshire, the Elliot family is considered the very best herein Bath, they could be understood to be socially beneath theircousins, the Dalrymples. Anne has vanity, and she is o ffended at the feeling that much(prenominal) unaccomplished and uninteresting people could beranked above her.Anne is unaccustomed to being thought beneath anyone, and in someways, she has more pride than her father and sister. She cannot bearthe thought that such a respected, landed family such as hers mustlive in rented rooms in a city, while their home is inhabited byothers. Anne is further dismayed at the small degree to which herfather and sister seem to be dysphoric by this. Austen is expressing thata certain amount of pride can be a good thing, if it is based upontrue merit and not dishonest appearances.

Aib Problem Solution

Aib Homework Wk3 Problem 1 The next data were obtained from a project to create a new portable electronic. act while Predecessors A 5 geezerhood &8212 B 6 eld &8212 C 8 eld &8212 D 4 geezerhood A, B E 3 long time C F 5 Days D G 5 Days E, F H 9 Days D I 12 Days G Step 1 Construct a network draw for the project. Step 2 make the following questions (15 points total) a) What is the Scheduled Completion of the Project? (2 points) 32 -> CORRECT b) What is the deprecative Path of the Project? (3 points) B,D,F,G,I -> CORRECT 2,4,6,7,9 c) What is the ES for practise D? (2 points) 6 -> Correct ) What is the LS for Activity G? (2 points) 15 e) What is the EF for Activity B? (2 points) 6 -> Correct f) What is the LF for Activity H? (2 points) 32 -> Correct g) What is the float for Activity I? (2 points) 0 Problem 2 The following data were obtained from a project to build a pressure vessel Activity distance Predecessors A 6 hebdomads &8212 B 6 weeks &8212 C 5 weeks B D 4 we eks A, C E 5 weeks B F 7 weeks D, E, G G 4 weeks B H 8 weeks F I 5 weeks G J 3 week I Step 1 Construct a network diagram for the project. Step 2 Answer the following questions (15 points total) ) mastermind the scheduled finish time. (3 points) 30 b) Identify the critical path (4 points) B,C,D,F,H c) What is the shirk time (float) for bodily function A? (2 points) 5 d) What is the slack off time (float) for body process D? (2 points) 0 e) What is the slack time (float) for act E? (2 points)4 f) What is the slack time (float) for activity G? (2 points) 5 Problem 3 The following data were obtained from a project to design a new software package Activity Duration Predecessors A 5 Days &8212 B 8 Days &8212 C 6 Days A D 4 Days C, B E 5 Days A F 4 Days D, E, G G 4 Days B, C H 3 Day GStep 1 Construct a network diagram for the project. Step 2 Answer the following questions (15 points total) e) lead the scheduled completion time. (3 points) 19 f) Identify the critical path(s) (4 poi nts) A,C,D,G,F g) What is the slack time (float) for activity B? (2 points) 3 h) What is the slack time (float) for activity D? (2 points) 0 e) What is the slack time (float) for activity E? (2 points) 5 f) What is the slack time (float) for activity G? (2 points) 0 Problem 4 The following data were obtained from an in-house MIS project Activity Duration PredecessorsA 5 Days &8212 B 8 Days &8212 C 5 Days A D 4 Days B E 5 Days B F 3 Day C, D G 7 Days C, D H 6 Days E, F, G I 9 Days E, F Step 1 Construct a network diagram for the project. Step 2 Answer the following questions (15 points total) a) Calculate the scheduled completion time. (3 points) 25 b) Identify the critical path (4 points) B,D,G,H c) What is the slack time (float) for activity A? (2 points) 2 d) What is the slack time (float) for activity D? (2 points) 0 e) What is the slack time (float) for activity E? (2 points) 3 f) What is the slack time (float) for activity F? (2 points) 1

Memory Recall History

Bibliography Cherry, Kendra. retrospect Retrieval Retrieving entropy from the Memory. Ab forth. com Psychology. The New York Times Company, n. d. Web. 22 Sept. 2012. Holladay, April. How Does the Human Memory Work? regular army Today. WonderQuest, 15 Mar. 2007. Web. 24 Sept. 2012. Mastin, Luke. Memory Recall/ Retrieval. The Human Memory. N. p. , 2009. Web. 22 Sept. 2012. Miller, Greg. How argon Memories Stored and Retrieved. Science Mag. AAAS, 1 July 2005. Web. 22 Sept. 2012. Mills, Kristen L. and Heather K. McMullan. A Study of short-run Memory Recall with Pictures, Words, and Pictures and Words Presented Together. National Undergraduate Research Clearinghouse Site. bit Western press out University, 22 Apr. 2004. Web. 22 Sept. 2012. Memory Recall Memory recall occurs when you access information stored in your brain without being cued. This occurs when you argon remembering simple things or taking a test. Two early(a) types of fund recall be recollection and recognition .Recollection is when you remember partial information. reference occurs when you identify information after experiencing it again (Cherry). Memories are stored into your brain employ medical temporal lobes, MLT (Miller). The job of MLT is to make memories using neural activities that are created in response to the senses (Mastin). Another part of the brain that helps with memories is the genus Hippocampus. The job of the hippocampus is to contain the new memories in the long-term or short-term memory (Holladay).One way of experimenting with memory recall was performed by Missouri Western State University. During this experiment people were given cards, some had but words, some had just pictures, and some had words and picture. These people were given a short totality of time until they were quizzed to see which group remembered what was on the card. The group that filled out the most information was the group that was given the words and pictures (Mills).

Advantages and Disadvantages of Using Computers Essay

I think this is an interesting topic when i am indeliberate in surfing some webs. And i wonder wherefore no one discuss this?. So, i am eager to put on the first writing . Nowa daylights, most of hatful know to wasting disease figurer. b atomic number 18ly what purposes they use it for ?. that s way we really recognize that it is so prominent or good to use computer. You know, up to the ages, we classify the benefits of computer are. For people who doing in big companies are required to know how to use computer for manage the project or totally composing the contract, speech the database, even making a important data security for firm.In fact, A great benefit that a computer certainly work effectively and as replaced thousands of people to solve the complex tasks by only one person or group. That save much money and era and even workers strength. And computer is the intelligent device for students to study, particularly IT students. They can search documents which are rel ated their curriculum or any(prenominal) information they are interested in their life on network if that computer has global network.On the other hand, most of people are tired after sitting with computer for work a extensive time in day, may relax their mind with many kinds of games they want, get word to music, study English and so on In a word, computer is the best device to everyone for many variety purposes. However, some people use computer for bad idea. it is nothing to useful for children are crazy for games day by day. That makes children dont continue to study and their marks is bit by bit lower and lower.Furthermore, it is easy to attract crazy children and student with depraved culture. In my opinion, our government are forbidding strictly behaviors uploading badly depraved things on internet. And certainly have to advice children and their parent to avoid putting bad those in their computer. I am strongly disagree people who make children go down in an our develop ing country who will be the main leader our country in the future.

Living at Home Versus Living in an Apartment Essay

People do not realize how distinguishable animate at domicile and financial support in an apartment is until they discriminate the two. Other people dont realize it until they ar in truth come out of the closet on their aver. There are many differences when a individual is donjon at home compared to spirit in an apartment. In this assay we will look at the differences of the two. One difference surrounded by living at home and living in an apartment is how the bills get paid. When living at home parents or whoever the more or lessbody lives with pays each the bills and buys entirely the nutrition. veritable(a) if the soul has to pay for anything while living at home, Im sure it is just a sm alone portion of what all the bills capture out to be. When living in an apartment the person has to pay their own bills and buy your own food. This gist that they lay down to find some(prenominal)where that is cheap for them. whatever apartments book bills kindred elect ricity, water, and sewer/garbage included in the rent. If the person needs sponsor buying food they lease a program out in that respect that they can sign up for food stamps at the local social services office.They also have places that have food pantries that gives people a food basket. Some towns also have a place for people to go and eat like the buyback Army or a church. This is one major difference of living at home versus living in an apartment. Another difference betwixt living at home and living in an apartment is devising sure the person has everything they need. When living at home with the persons parents or whoever they live with, they already have or have bought all the necessities that they will need for a place like furniture, pots and pans, cleaning supplies, jam for hygiene, etc.When a person is living in an apartment they have to buy everything that they are red to need for the apartment. That means that the person has to go out and buy their own furniture and everything else that they postulate for their place. A person can watch for garage sales or even go check out some thrift stores. The Salvation Army gives a person a voucher to go to their store and get some stuff for their new place if they have it in stock. They even help out with furniture to.Some stuff the person will plausibly want brand new like their silverware and dishes. Another difference amid living at home and living in an apartment is all about how clean the place is. When someone lives at home or with whomever they live with they usually want their place nice and clean. They want everyone that lives there to help with the cleaning and to maintain a clean home. When a person lives in an apartment they are the one that decides when to clean the place. excessively they are the one to decide how clean they want their place and if they are going to try and maintain a clean place. Some people like their house spotless while others dont really business if their place is clean or not. Maintaining a clean home means a lot to others when they come over to visit. The final difference betwixt living at home and living in an apartment is world independent. When a person is living at home they have rules to follow. Some rules may be easy to follow like cleaning up after oneself, help with the cooking, and maintain a job or go to school.Other rules may be harder to follow like if the person has a certain time to be home and if certain people that they string out with are not allowed to be at the persons house they are staying at because they dont like or get along with them. When a person is living in an apartment they are on their own. They are the one that picks the rules. When living in an apartment a person can come and go as they please. Also they can do whatever they want. Just be careful when living in a persons own apartment because some people go crazy and have all kinds of parties.If the neighbors call the cops the landlord has a right to e vict them. If they get evicted it makes it hard for them to get an apartment the attached time they are looking for one. In conclusion, everybody now has some of the differences between living at home and living in an apartment. Its all up to them to decide if they want to stay living at home or move into an apartment. Everybody has their own way of thinking and choosing what they want to do. If they want to move into an apartment a person could keep an eye out for stuff they will need so they will have it by the time they move.

Bulletin Board with Wireless Digital Display Essay

This project aims to fashion a receiving set transmittance of data to a publicise get along with for announcements, advertisements and sending of any kinds of edifying statements that pass on be useful for readers, employees and students.2.1 Problem StatementElectronic bulletin board foundationnot update in normalation time by time. Our transcription idler provide ready- do templates so that time by time, we can reassign the appearance base on the activity to be post. Especially the powers device can provide a wireless transmittance of data to bulletin board with different displays.To achieve the goal, the proponents will be addressing the following problems.2.1.1 General ProblemHow to ready a PC ground Bulletin Board with Wireless digital Display System?2.1.2 proper(postnominal) Problems2.1.3.1 How to create a wireless device that can send data from a data processor to a monitor?In updating the posts in the bulletin board, the in-charge personnel need to go over the bulletin board personally just to change and update the posts. 2.1.3.2 How to create the softwargon for the messages to be displayed?In manual updating of information in the bulletin board, the posts should be printed in the paper before posting. 2.1.3.3 How to create log-in module strategy for the security of the user?Unauthorized person could access the information to be posted in the bulletin board. 2.1.3.4 How to create a module that can pull strings the messages to be displayed?It consumes time updating the information to be posted in the bulletin board, the authorized personnel is required to update the post in a timely manner.2.1 Proposed Research Project2.2.1 General ObjectivesTo create a PC establish Bulletin Board with Wireless Digital Display System.The proponents will create a device that provides a wireless transmission of data to bulletin boards with different display.2.2.2 Specific Objectives2.2.3.1 To create a wireless device that can send data from a computer to a monitor.The proponents will be using a Wi-Fi router for the transmission of data for the LCD display and will create a RF transmitter for the transmission of data for the lead display. 2.2.3.2 To create the software program for the messages to be displayed.The proponents will be using Flash Software for the manipulation of the messages to be displayed in the bulletin board. 2.2.3.3 To create log-in transcription for the security of the users.The proponents will create a log-in frame by using optical basic 6.0 for the security of the bulletin board. 2.2.3.4 To create a module that can control the messages to be displayed.The proponents will create a module using Visual Basic 6.0 that can control multiple displays in the bulletin board.2.2.3 chain of mountains and LimitationsScope* The system can accommodate multiple displays with a iodine controller. * The system can display static and scrolling messages.* The system can float videos through a wireless transmission. * The system has a default conceal messages.* The information to be displayed is queued.* The controller sends information in an LCD and LED display wirelessly.Limitations* Distance of the controller from the monitor is limited. * Editing of messages is done manually by a duly authorized person. * This bulletin board is for interior purposes only.2.2 MethodologyThe proponents will be using the cycle of PROTOTYPING METHOD to turn over the project.PROTOTYPING METHODa. Requirements AnalysisA prototyping model begins with requirements analysis, and the requirements of the system are define in detail. The user is interviewed in order to know the requirements of the system.b. DesignWhen requirements are know, a preliminary design or quick design for the system is created. It is not a detailed design, however, and includes the important aspects of the system, which gives an idea of the system to the user.c. story DesignInformation gathering from quick design is modified to form a protot ype. It represents a rough design of the required system.d. PrototypingA partly developed product that enables customer and developers to examine some aspect of the proposed system and decide if its suitable or appropriate to the finish product.e. faceThe process of combining ideas into a congruous object of thought that based on the paper design. Satisfying certain conditions as part of result a problem.f. Unit and integration interrogationThe phase in software testing in which individual software modules are combined and time-tested as a group. It occurs after unit testing and before governance testing. Integration testing takes as its input modules that have been unit tested, groups them in larger aggregates, applies tests defined in an integration test plan to those aggregates, and delivers as its output the integrated system ready for system testing.g. System testingDocument Settings must be defined where each types of documents types consists its custom made layouts that suits business processes. Basically document layouts setup or linked to the documents view are default document layout that are standard layout that complies with the companys standard business process.h. Acceptance testingTesting generally involves path a suite of tests on the completed system. Each individual test, known as a case, exercises a particular operating condition of the users environment or features of the system, and will result in a pass or fail, or Boolean outcome. There is generally no degree of success or failure.i. Operation and maintenanceIn production, system requires updates, changes and maintenance from time to time so system can track down properly. This phase goes on for entire life time of the system. PFLET998 (Fig 1.0 sees at addition B)

Ancol Ltd.

1. What are the background facts, enigmas and symptoms of the problems that suggest that something has gone wrong?Background Facts As Mr. Simard joined Ancol Ltd., he initially observed that there was a sulphurous relationship amongst employees and management. He wanted to bridge the open and tear both sides together for a better communicative understanding among them. His belief was that, if a certain measure of trust could be make amongst employees and management, indeed it would create a better working environment, reduce the filter level at work, as well increase productivity amongst employees due to job satisfaction, which would lead to greater growth for the face. In order to piss this, his first move was to remove the clock governing body for employees to record their sacking reports. The idea behind this was that employees will be able to work oft freely realizing management has put certain level of trust in them.Problems and Symptoms of Problems The main idea behind removing the clocking system was to improve relationships between employees and management. Although, this was a positive intention from Mr. Simard even, he overlooked some strike measures to achieve his objectiveDid not do enough research to light upon if similar approach was taken in the past within the plaque or elsewhere, and identify whether there was all business risks associated with his decision. Did not converse his decision with higher(prenominal) management, or the workers union. Failed to understand the competence level of the supervisors and their true roles and responsibilities prior to implementing the process Failed to discuss with payroll and understanding possible personal effects of operational decisions causing problems within other departmentsThe symptoms of problems started when employees realized that they were no time-consuming being monitored for their attendance, and there was an incompetency amongst the supervisors to detect all misuse. As a result, a small percentage of employees took advantage of the situation, leaving a vast number of employees feeling unsatisfied with the situation due to inequality at workplace.2. In your opinion, what caused these problems and whose responsibility is it to solve them? What solutions can you suggest?In my opinion, the problem was caused by lack of planning for such(prenominal) decisions. There were hardly any communication between Mr. Simard and the rest of the organization in making such moves. He also lacked communication with the union, as well as higher management. There was lack of training available for the supervisors to track and manage attendance of their employees. There is no evidence of a productivity monitor system for each employee, which could have also assisted in reporting any misuse.I strictly believe, it is still Mr. Simards responsibility to resolve them, by educating his supervisors on how to track attendance, and also by maintaining a clear communication wi th the employees that an organization can only benefit by filling in the gap between employees and management through trust, honestly and hardwork. There should also be examples made of the employees who have misused their liberty by either upshot or suspension. He should also keep an open communication with the labor union and report those employees that have misused.He needs to implement a productivity monitoring system, which can track the production of each employee. Although this might be viewed as a negative amongst some members however, if there are rewards associated with it (i.e employee of the month, or incentives), then that might also create employee satisfaction. I honestly dont believe that going back to the clocking system will do any good, the decision that Simard made was a positive one however he just needed to plan it better.

Good and Bad Dams

Latin America and Caribbean Region sustainable learning Working root word 16 Good dam ups and murderedly Dams Environmental Criteria for Site Selection of hydroelectric attends November 2003 George Ledec Juan David Quintero The arna depose Latin America and Caribbean Region environmentally and sociablely sustainable suppuration De secernatement (LCSES) Latin America and the Caribbean Region Sustainable Development Working report card No. 16 Good Dams and ruinous Dams Environmental Criteria for Site Selection of hydroelectric Projects November 2003George Ledec Juan David Quintero The instauration Bank Latin America and the Caribbean Region environmentally and Socially Sustainable Development welkin Management Unit George Ledec has worked with the field Bank since 1982, and is presently Lead Ecologist for the Environmentally and Socially Sustainable Development Unit (LCSES) of the World Banks Latin America and Caribbean regional Office. He specializes in the environmenta l discernment of education projects, with particular focus on bio regeneration and link conservation oncerns. He has worked ex ten dollar billsively with the environmental aspects of obturates, roads, oil and gas, forest management, and protected argonas, and is one of the briny authors of the World Banks cancel Habitats Policy. Dr. Ledec earned a Ph. D. in Wildland Resource Science from the University of California-Berkeley, a Masters in Public personal matters from Princeton University, and a Bachelors in Biology and Environmental Studies from Dartm step to the foreh College.Juan David Quintero joined the World Bank in 1993 and is presently Lead Environmental Specialist for LCSES and Coordinator of the Banks Latin America and Caribbean Quality Assurance Team, which monitors compliance with environmental and neighborly safeguard policies. He specializes in environmental assessment of infrastructure projects, primarily roads, hydro bureau, oil and gas, urban transport, and we t supply and sanitation. He has received the Regional Award from the International Association for Impact Assessment (IAIA) for promoting improvements in environmental reach assessments without Latin America.He is a well-behaved engineer with graduate student degrees in Environmental and Sanitary Engineering. The findings, interpretations, and conclusions in this document argon those of the authors, and should non be attributed in any manner to the World Bank, its affiliated organizations, members of its posting of executive director Directors, or the countries they represent. This working piece of music series is produced by the Environmentally and Socially Sustainable Development Sector Management Unit of the Latin America and Caribbean Regional Office. Additional copies whitethorn be pay offed from the authors or from LCSES chopine Assistant Peter Brandriss (email&160protected rg, or tel. 1-202-473-9379). C everywhere photos (clockwise from focal ratio left) Loksop D am, southbound Africa Guavio Dam, Colombia Yacyreta Dam, Argentina/Paraguay All photos by George Ledec ii Contents Acknowledgments .. iv preface .. v Executive Summary ii Introduction 1 unfavourable Environmental Impacts of Hydro origin Development 3 Key Indicators of potential Environmental Impacts .. 9 Overview of Environmentally Good and Bad hydroelectric Dam Sites 13 Conclusions .. 5 Bibliography. 17 tabularises 1. Hydroelectric Projects indecent Impacts and temperance Options 4 2. Land playing ara Flooded and spate Displaced in Large Hydropower Projects iii 12 Acknowledgments Doug mason (consultant) compiled information on more than twenty complete Latin Ameri give the gate hydroelectric projects this information was real utilitarian in our analysis of environmental and genial impacts, mitigation measures, and send selection criteria.Several current and former World Bank Group staff members provided useful comments and oft encouragement, including Aless(pre nominal)andro Palmieri, John Briscoe, Teresa Serra, Tony Whitten, Robert Goodland, Tor Ziegler, warren Van Wicklin, William Partridge, Maria Clara Mejia, Kristine Ivarsdotter, Mateen Thobani, Salman Salman, and A. J. Glauber. This cover also reflects the helpful comments provided by Dominique Egre and Gaitan Guertin (Hydro-Quebec), Jose Goldemberg (World missionary work on Dams), and Paul Dulin. Peter Brandriss helped edit and prep ar the bill for publication. iv ForewordFew types of development projects arouse as practically controversy as hydroelectric dekameters. Their often serious environmental disparage has been amply documented deep down the past decade. Nonetheless, umteen countries, in Latin America and world huge, rely upon hydroelectric decameters for a major ascribe of their electric power. Electricity cadaver a key ingredient for improving the lives of poor people al al near everywhere. In developing countries, rapid urbanization and wrap upd population g rowth pass on look into increased demand for electric power for decades to come, still with the closely successful of demand management and energy efficiency measures.Energy planners in many developing countries atomic itemise 18 thus in all probability to continue seeing hydroelectric dekametres as a promising source of renewable electric power. This composition provides cardinal advice for substantially reducing the environmental damage from future hydroelectric dams (whether or non they receive World Bank Group financing) by spuriouss of inviolable project site selection. Although the reports conclusions atomic proceeds 18 draw primarily from a review of Latin Ameri tummy dams, its innovative methodology for dam site selectionbased on robust environmental and social criteria and straightforward, quantitative indicatorsshould prove useful worldwide.The report also help to the full summarizes the environmental mitigation options for the improved operation of exis ting hydroelectric dams. As such, this report should be of considerable pastime to people interested in hydroelectric dams, whether at the World Bank, opposite multilateral and bilateral development institutions, government agencies, private energy companies, consulting firms, environmental and another(prenominal)(a) NGOs, and academia. This report is part of the LCR Sustainable Development Working Paper Series published by the Latin America and the Caribbean Regions Environmentally and Socially Sustainable Development Sector Management Unit (LCSES).This series seeks to disseminate the results of our analytic and operational work, present preliminary findings, and describe best practices with respect to major sustainable development issues facing the region. The findings, interpretations, and conclusions expressed in these papers atomic identification number 18 entirely those of the authors and should not be attributed to the World Bank, members of its Board of Executive Dir ectors, or the countries they represent. John Redwood Director Environmentally and Socially Sustainable Development Latin America and Caribbean Region The World Bank v Executive SummaryLarge dams vary considerably in their indecorous environmental and related social impacts. From an environmental standpoint, there atomic number 18 relatively safe dams and bad dams. art object or so extensive dams are relatively favorable, others admit ingestd major environmental damage. The severity of environmental impacts from a hydroelectric project is rangyly fixed by the dam site. succession dams at sound sites weed be very defensible from an environmental standpoint, those proposed at bad sites go a demeanor infixedly be elevatedly elusive, even if all feasible mitigation measures are in good order implemented.This paper provides a simple, yet robust, methodology for comparing proposed hydroelectric project sites in scathe of their expected negative environmental impacts, a nd relating these to power time benefits. The paper also summarizes the environmental mitigation options for full-size dams. If properly implemented, these mitigation measures domiciliate impressively prevent, besmirch, or compensate for many (though not all) of a hydroelectric projects negative impacts.Nonetheless, the most effective environmental mitigation measure is good site selection, to ensure that the proposed dam will draw relatively minuscular damage in the freshman place. The paper presents quantitative indicators (using data that are relatively easy to obtain) for paygrade and ranking proposed new hydroelectric projects in terms of their seeming untoward environmental impacts. Projects with a dinky informant surface realm (relative to power multiplication) tend to be most desirable from both an environmental and social standpoint, in part be stir they minimize pictorial habitat deprivationes as well as resettlement needs.In general, the most environment ally benign hydroelectric dam sites are on upper tributaries, small-arm the most problematic ones are on the macro briny stems of rivers. Power expansion prep should ensure that environmental criteria, of the type outlined in this paper, are brainiaced(p) discriminate weight in hydroelectric project site selection. many another(prenominal) of the more problematic dam sites are best left undeveloped, because the environmental or related social impacts are likely to be unacceptably high. In those cases, other power generation technologies are likely to be more environmentally desirable.Conversely, hydroelectric dams at good sites (with relatively piteous wayward impacts) and with effective implementation of proper mitigation measures are likely to be more attractive from an environmental standpoint than the most likely power generation selections. vii Introduction 1. Large hydroelectric dams are among the most controversial of all types of development projects. They founder been the focus of much criticism of the World Bank and other international financing agencies. The great dams debate is often highly polarized.Critics of macroscopical hydroelectric projects point to a wide range of negative environmental and related social impacts, from the close of unique biodiversity to the displacement of vulnerable valet de chambre populations. Defenders of ample dams note that they are often the economically least-cost source of electric power available, specially to large urban centers they are a renewable electrical energy source and most other power generation technologies also imply signifi open firet ominous environmental impacts. 2.Worldwide, many countries rely upon hydropower for a substantial serving of their electricity. In developing countries, rapid urbanization and continued population growth will ensure increased demand for electric power for decades to come, even with the most successful of demand management and energy efficiency measur es. Electricity remains a key ingredient for improving the lives of millions of poor people doneout the developing world. Energy planners in many countries are likely to continue seeing hydroelectric dams as a promising, renewable source of electricity.Major new-made international initiativesincluding the World Summit on Sustainable Development (Johannesburg, 2002), World Water Forum (Kyoto, 2003), World Commission on Dams (1997-2002), and the ongoing Dams and Development Project of the United Nations Environment Program nurse reaffirmed the commitment of many governments and international agencies (including the World Bank) to hydropower development, but in a manner which richly reflects modern environmental concerns. 3. In this context, it is important to remember that all large hydroelectric dams are not alike.Large hydroelectric projects vary tremendously in the extent of their unfavourable environmental and related social impacts. (In this paper, we define large hydroelect ric dams as those with 10 megawatts or more of installed generating substance, to distinguish them from small or micro-dams which generate power on a small scale. ) For example, the dmegawatt Pehuenche Hydroelectric Project in Chile outpouringed only most 400 hectares of land (with minimal damage to forest or wildlife resources) and has had no peeing flavour problems.By contrast, the Brokopondo Dam in Suriname flood about 160,000 hectares of biologically valuable tropical rainforest and is known for serious piddle quality and aquatic stinkpot problems, while providing relatively little electric generating capacity (only 30 megawatts). 4. We conducted a review of more than twenty absolute hydroelectric dam projects in Latin America, along with several well-known projects from other regions. Our study found that close to large dams are relatively benign, while others have caused substantial environmental and related social damage.This paper provides a methodology for comf ortably comparing proposed hydroelectric project sites in terms of their expected adverse environmental impacts, relative to their power generation benefits. The expert criteria and quantitative indicators in this paper should be viewed as completing to 1 2 LCR Sustainable Development Working Paper No. 16 the broader and often more process-oriented advice of other recent reports on dams, including the 2000 Dams and Development report of the World Commission on Dams.This papers recommendations are fully compatible with the World Banks Water Resources Sector Strategy, although this paper provides more technical detail regarding specific environmental impacts, mitigation options, and site selection criteria. Adverse Environmental Impacts of Hydropower Development 5. The range of adverse environmental and related social impacts that tush result from hydroelectric dams is remarkably diverse. While about impacts amount only during eddy, the most important impacts unremarkably are over due(p) to the long-term existence and operation of the dam and source.Other significant impacts can result from complementary civil works such as door roads, power infection lines, and quarries and hook on pits. put off 1 summarizes the adverse environmental and social impacts associated with dams and rootages, along with the typical kinds of mitigation measures often proposed (and, less often, in effect implemented). 6. Our analysis indicates that with properly implemented mitigation measures, many of the negative environmental and related social impacts of hydroelectric projects can be reduced to very accep circumvent trains.As outlined in Table 1, mitigation measures can efficaciously prevent, minimize, or compensate for most adverse impacts, but only if they are properly implemented. In our review of Latin American hydroprojects, we found wide variation in the extent to which environmental mitigation measures were planned, budgeted, and actually implemented. 7. Mor eover, for some types of negative impacts, at some project sites, the available mitigation measureseven when properly implementedare inherently unsatisfactory.Examples of adverse environmental impacts which croak at some hydroelectric projects and cannot be fully mitigated involve (i) irreversible biodiversity disadvantage, if vital inborn habitats not occurring elsewhere are semiaquatic (or left dry) by the dam (ii) search passage facilities frequently cannot mend the pre-dam ecological balance of a river, in terms of species composition or tip migrations and (iii) some cultural property (including sacred sites) cannot be adequately salvaged prior to reservoir inundation. 8.Thus, because mitigation measures are often not fully implemented, and are sometimes inherently inadequate, the iodin most important environmental mitigation measure for a new hydroelectric project is good site selection, to ensure that the proposed dam is will be largely benign in the number 1 place. In the fol imprinting summary of typical adverse environmental impacts and corresponding mitigation options, it is important to keep in mind that all these types of impacts can be either avoided or minimise through good project site selection. 3 4Note All of these impacts can be avoided or minimized by good dam site selection, the single most important environmental measure. Environmental Impacts relief Options Impacts of the Dam and rootage Flooding of Natural Habitats Some reservoirs permanently flood extensive natural habitats, with topical anaesthetic and even global extinctions of animal and plant species. Very large hydroelectric reservoirs in the tropics are especially likely to cause species extinctions (although such losses are only infrequently documented due to the lack of scientific data).Particularly hard-hit are riverine forests and other riparian ecosystems, which naturally occur only along rivers and streams. From a biodiversity conservation standpoint, the terr estrial natural habitats garbled to flooding are ordinarily much more valuable than the aquatic habitats created by the reservoir. One occasional exception to this rule is that shallow reservoirs in dry zones can provide a permanent oasis, sometimes important for migrant piddlefowl and other terrestrial and aquatic fauna.To offset the loss of natural habitats to reservoir flooding or other project components (such as borrow pits), one or more compensatory protected stadiums can be established and managed under the project. If an existing area is protected on paper only, a useful project option is to strengthen its onthe-ground bulwark and management. The area protected under the project should ideally be of comparable or greater size and ecological quality to the natural area confounded to the project.Under the World Banks Natural Habitats Policy, hydroelectric and other projects should not be sited where they would cause the significant conversion or degradation of critical n atural habitats that do not occur elsewhere (and, hence, cannot be adequately compensated). Loss of Terrestrial Wildlife The loss of terrestrial wildlife to drowning during reservoir filling is an inherent consequence of the flooding of terrestrial natural habitats, although often treated as a separate impact. Although they whitethorn be useful for public traffic purposes, wildlife rescue efforts rarely succeed in restoring wild populations.Instead of drowning, the captured and relocated animals typically starve, are killed by competitors or predators, or fail to reproduce successfully, due to the limited carrying capacity of their new habitats. Wildlife rescue is most likely to be middlingified on conservation grounds if (a) the species rescued are globally threatened with extinction and (b) the relocation habitat is ecologically suitable and efficaciously protected. However, the money spent on rescue would usually do much more for wildlife conservation if it were invested in co mpensatory protected areas.The most effective way to minimize wildlife mortality in hydroelectric projects is to opt dam sites which minimize the wildlife habitat flooded. LCR Sustainable Development Working Paper No 16 Table 1. Hydroelectric Projects Adverse Environmental Impacts and Mitigation Options Environmental Impacts Mitigation Options Involuntary Displacement Involuntary displacement of people is often the main adverse social impact of hydroelectric projects. It can also have important environmental implications, such as with the conversion of natural habitats to carry resettled rural populations.For physical displacement, the main mitigation measure is the resettlement of displaced populations, including new housing, replacement lands, and other material assistance, as needed. Success usually requires consultation and participatory decisionmaking by both the resettled and host populations (mandatory for World Banksupported resettlement). Effective resettlement of vulnera ble ethnic minorities is peculiarly challenging because some of these people are highly vulnerable to adverse social changes.Accordingly, the World Banks Involuntary Resettlement and natal Peoples policies afford special consideration to these populations, specifying that, among other requirements, all viable alter inborn project designs should be explored sooner considering physical displacement for these groups. For people who are not physically displaced but suffer an economic loss of livelihoods (based on angleeries, rural or grazing lands, river-edge clay for brick and tile production, or other resources), mitigation measures should involve the provision of replacement resources, new job training, or other income restoration assistance, as needed.Deterioration of Water Quality The damming of rivers can cause serious weewee quality deterioration, due to the reduced oxygenation and dilution of pollutants by relatively stagnant reservoirs (compared to fast-flowing rivers), f looding of biomass (especially forests) and resulting underwater decay, and/or reservoir stratification (where deeper lake water lack oxygen).Water pollution stop measures (such as sewage treatment plants or enforcement of industrial formulas) may be needed to improve reservoir water quality. Where poor water quality would result from the decay of flooded biomass, discriminating forest clearing within the impoundment area should be completed forwards reservoir filling. Downriver Hydrological Changes These adverse impacts can be minimized through attentive management of water releases.Objectives to consider in optimizing water releases from the turbines and spillways intromit adequate downriver water supply for riparian ecosystems, reservoir and downriver slant survival, reservoir and downriver water quality, aquatic weed and disease vector control, irrigation and other human uses of water, downriver flood protection, cheer (such as whitewater boating), and, of course, powe r generation. From an ecological standpoint, the ideal water release conformation would usually closely mimic the natural flooding government activity (although this may not be feasible for densely settled floodplains where flood protection is a high priority).Dams that generate baseload electricity are typically more capable of replicating near-natural downriver flows than those that produce peaking power (where daily water releases may fluctuate sharply, often to the detriment of aquatic organisms that are adapted to less frequent flow changes). Environmental management plans for hydroelectric projects should specify environmental water releases, including for dams owned or operated by the private sector. Good Dams and Bad Dams 5Major downriver hydrological changes can destroy riparian ecosystems dependent on biannual natural flooding, exacerbate water pollution during lowflow periods, and increase saltwater encroachment near river mouths. Reduced depository and nutrient load s downriver of dams can increase river-edge and coastal erosion and damage the biological and economic productiveness of rivers and estuaries. Induced desiccation of rivers infra dams (when the water is diverted to another portion of the river, or to a different river) kills fish and other fauna and botany dependent on the river it can also damage agriculture and human water supplies.Mitigation Options Water-Related Diseases Some infectious diseases can tail cover around hydroelectric reservoirs, particularly in warm climates and densely populated areas. Some diseases (such as malaria and schistosomiasis) are borne by water-dependent disease vectors (mosquitoes and aquatic snails) others (such as dysentery, cholera, and hepatitis A) are spread by contaminated water, which frequently becomes worse in stagnant reservoirs than it was in fast-flowing rivers.Corresponding public health measures should include preventive measures (such as awareness refugee campaigns and window scree ns), monitoring of vectors and disease outbreaks, vector control, and clinical treatment of disease cases, as needed. Control of floating aquatic widows weeds (see below) near populated areas can reduce mosquito-borne disease risks. Fish and Other Aquatic life-time Hydroelectric projects often have major effects on fish and other aquatic life. Reservoirs positively affect certain fish species (and fisheries) by ncreasing the area of available aquatic habitat. However, the net impacts are often negative because (a) the dam blocks upriver fish migrations, while downriver passage through turbines or over spillways is often unsuccessful (b) many riveradapted fish and other aquatic species cannot survive in artificial lakes (c) changes in downriver flow patterns adversely affect many species, and (d) water quality deterioration in or below reservoirs (usually low oxygen levels sometimes gas super-saturation) kills fish and regaining aquatic habitats.Freshwater molluscs, crustaceans, an d other benthic organisms are even more polished to these changes than most fish species, due to their limited mobility. Management of water releases may be needed for the survival of certain fish species, in and below the reservoir. Fish passage facilities (fish ladders, elevators, or trap-and-truck operations) are intended to help migrant fish move upriver past a dam they are usually of limited effectiveness for various reasons (including the difficulty of ensuring safe downriver passage for many adults and fry).Fish hatcheries can be useful for maintaining populations of native species which can survive but not successfully reproduce within the reservoir. They are also often used for stocking the reservoir with economically desired species, although introducing non-native fish is often devastating to native species and not ecologically desirable. Fishing regulation is often essential to maintain viable populations of commercially valuable species, especially in the waters immedi ately below a dam where migratory fish species concentrate in high numbers and are by artificial means easy to catch.Floating Aquatic Vegetation Floating aquatic vegetation can rapidly proliferate in eutrophic reservoirs, causing problems such as (a) flying habitat for most species of fish and other aquatic life, (b) improved gentility grounds for mosquitoes and other nuisance species and disease vectors, (c) impeded navigation and swimming, (d) congest of electro-mechanical equipment at dams, and (e) increased water loss from some reservoirs. Pollution control and pre-impoundment selective forest clearing will make reservoirs less contributory to aquatic weed growth.Physical removal or containment of floating aquatic weeds is effective but imposes a high and recurrent expense for large reservoirs. Where compatible with other objectives (power generation, fish survival, etc. ), occasional drawdown of reservoir water levels may be used to kill aquatic weeds. Chemical drunkennes s of weeds or related insect pests requires much environmental circumspection and is usually best avoided. LCR Sustainable Development Working Paper No 16 Environmental Impacts (table continues on following page) 6 Table 1.Hydroelectric Projects Adverse Environmental Impacts and Mitigation Options (continued) Environmental Impacts Mitigation Options Loss of Cultural space Cultural property, including archaeological, historical, paleontological, and unearthly sites and objects, can be fill by reservoirs or destroyed by associated quarries, borrow pits, roads, or other works. Structures and objects of cultural interest should undergo salvage wherever feasible through scientific inventory, careful physical relocation, and documentation and stock in museums or other appropriate facilities.However, it is often not possible to replace the loss of, or damage to, unique or sacred sites which may have great religious or ceremonial significance to indigenous or other local people. Reservo ir Sedimentation Over time, live storage and power generation are reduced by reservoir depositary, such that much of some projects hydroelectric energy might not be renewable over the long term. If effectively implemented, washstand management can minimize sedimentation and extend a reservoirs useful physical life, through the control of road construction, mining, agriculture, and other land use in the upper catchment area.Protected areas are sometimes established in upper catchments to reduce sediment flows into reservoirs, as with the Fortuna Dam in Panama and the proposed Rio Amoya (Colombia) and Nam Theun II (Laos) projects. Aside from watershed management, other sediment management techniques for hydroelectric reservoirs may at times be physically and economically feasible they include, among others, upstream check structures, protect dam outlets, reservoir flushing, mechanical removal, and increasing the dams height. babys room Gases Greenhouse gas releases from reservoirs can be reduced by a primitive salvage of commercial timber and fuelwood, although frequently this does not happen because of (a) high extraction and transportation costs, (b) marketing constraints, or (c) political and economic pressures not to delay reservoir filling. The surest way to minimize greenhouse gas releases from reservoirs is to choose dam sites that minimize the flooding of land in general, and forests in particular. table continues on following page) Good Dams and Bad Dams 7 Greenhouse gases (carbon dioxide and methane) are released into the atmosphere from reservoirs that flood forests and other biomass, either slowly (as flooded radical matter decomposes) or rapidly (if the forest is cut and burned before reservoir filling). Greenhouse gases are widely considered to be the main cause of human- generate global climate change. Many hydroelectric reservoirs flood relatively little forest or other biomass.Moreover, most hydroprojects generate sufficient electricity to more than offset the greenhouse gases which would otherwise have been produced by electrocution fossil fuels (natural gas, fuel oil, or coal) in power plants. However, some projects which flood extensive forest areas, such as the Balbina Dam in Amazonian Brazil, break through to emit greenhouse gases in greater amounts than would be produced by burn natural gas for many years of comparable electricity generation. Mitigation Options Impacts of Complementary Civil Works Access RoadsNew access roads to hydroelectric dams can induce major land use changes particularly deforestationwith resulting loss of biodiversity, accelerated erosion, and other environmental problems. In some projects (such as Arun II in Nepal), the environmental impacts of access roads can greatly exceed those of the reservoir. The siting of any new access roads should be in the environmentally and socially least damaging corridors. Forests and other environmentally mass medium areas along the chosen road corrid or should receive legal and on-the-ground protection.Road engineering should ensure proper drainage, to protect waterways and minimize erosion. Environmental rules for contractors (including penalties for noncompliance) should cover construction camp siting, gravel extraction, waste disposal, avoiding water pollution, worker behavior (such as no hunting), and other construction practices. See Ledec and Posas (2003) for details. Power Transmission Lines Power transmission line rights-of-way often reduce and fragment forests indirectly, they occasionally facilitate shape up deforestation by improving physical access.Large birds are sometimes killed in collisions with power lines, or by electrocution. Power lines can also be aesthetically objectionable. Power lines should be sited to minimize these concerns and built using good environmental practices (as with roads). In areas with concentrations of vulnerable bird species, the top (grounding) wire should be made more visible with pla stic devices. Electrocution (mainly of large birds of prey) should be avoided through bird-friendly tower design and proper spacing of conducting wires.Quarries and Borrow Pits Quarries and borrow pits are used to provide material for construction of the dam and complementary works. They can considerably increase the area of natural habitats or agricultural lands that are lost to a hydroelectric project. To the greatest extent feasible, quarries and borrow pits should be sited within the future inundation zone. Where this is not feasible, the pits should be rehabilitated after(prenominal) use, ideally for conservation purposes such as wetland habitats. Impacts of Induced DevelopmentAssociated Development Projects Hydroelectric dams often make possible new development projects with major environmental impacts, including irrigation, urban expansion, and industrial facilities (due to new water supplies). New development projects should be planned to minimize adverse environmental and social impacts. Environmental impact assessment studies should be carried out in the early stages of project grooming the resulting environmental mitigation plans should be fully implemented. Additional DamsThe construction of the first dam on a river can make the subsequent construction of redundant dams more economical, because flow regulation by the upriver dam can enhance power generation at the downriver dam(s). The environmental impact assessment study for the first dam on any river should include a cumulative environmental assessment of the likely impacts of proposed additional dams on the same river system. Implementation of mitigation measures for cumulative (rather than dam-specific) impacts should be completed or well underway prior to construction of the second dam on the river. LCR Sustainable Development Working Paper No 16Environmental Impacts 8 Table 1. Hydroelectric Projects Adverse Environmental Impacts and Mitigation Options (continued) Key Indicators of Likely Environmental Impacts 9. Before a dam site is chosen (with a project-specific environmental impact assessment), sector-level environmental analysis can rank potential sites according to their degree of environmental desirability. A sectoral environmental assessment (SEA) should be carried out prior to making major power sector planning decisions, especially in the comparison of hydroelectric and other power generation (and demand management) alternatives.However, even without a detailed SEA, it is possible to carry out a simple environmental and ranking of different hydropower sites using basic, often readily available technical data. There exist various quantitative, easily metrical indicators that can be used to estimate the extent of adverse environmental impacts for any proposed hydroelectric project. 10. This paper presents 13 quantitative, easily calculated indicators that we consider especially useful for hydroproject site selection from an environmental standpoint. These i ndicators have high predictive value for likely adverse environmental (and related social) impacts.The first nine indicators (AI) use information that is normally easy to obtain from basic dam planning data, even without a separate environmental study. The other four indicators (JM) are also very important in the environmental comparison of alternative dam sites, but involve data that may require further environmental (or resettlement) study to obtain. Indicator A (hectares of land inundated) is perhaps the single most useful one in predicting the degree of environmental damage, because this indicator is positively correlated with many of the others.From a social standpoint, the number of people requiring resettlement (Indicator J) is an especially important. A. Reservoir scrape up Area 11. The area flooded by the reservoir is a sloshed proxy variable for many environmental and social impacts (Goodland, 1997). A large reservoir area implies the loss of much natural habitat and wil dlife and/or the displacement of many people. Very large reservoirs are typically in the low-lyings (often with tropical disease and aquatic weed problems) and usually impound larger rivers (with more fish and other aquatic species at risk).A very useful measure of environmental costs relative to economic benefits is the ratio of inundated hectares per megawatt (ha/MW) of electricity it varies by four orders of magnitude for large power projects (see Table 2). The global average for all large hydroelectric dams constructed to date (not just those in Table 2) is about 60 ha/MW (J. Goldemberg, pers. comm. ) it would be environmentally highly desirable for this average to be much reduced in future hydroprojects. B. Water Retention Time in Reservoir 12.Mean water retention time during normal operation (the shorter, the better) is very useful in estimating the extent to which reservoirs will have long-term water quality problems. This foretell (number of days) is calculated as a funct ion of reservoir intensity (cubic meters) and mean river flow (cubic liters per second). 9 10 LCR Sustainable Development Working Paper No. 16 C. Biomass Flooded 13. Biomass flooded is calculated in dozens per hectare based on the percent cover of different vegetation types in the reservoir area.For good reservoir water quality, dams should minimize flooding of forests (which have high biomass content). Flooding native forests also threatens biodiversity and releases greenhouse gases. D. Length of River Impounded 14. To observe aquatic and riparian biodiversity (including riverine forests), dam sites should minimize the length (kilometers) of river (main stem overconfident tributaries) impounded by the reservoir (measured during high flow periods). E. Length of River Left alter 15. This measures the kilometers of river left dry (with less than 50 percent of dry gentle mean flow) below the dam, due to water diversion.The length of dried-up river bed (before the next important d ownstream bird feeder) should be minimized, due to the loss of fish and other aquatic life, damage to riparian ecosystems, and disruption of human water supplies, agriculture, and/or fishing. F. Number of Downriver Tributaries 16. The more (major, undammed) tributaries downriver of the dam site, the better, in terms of maintaining accessible habitat for migratory fish, the natural flooding regime for riverine ecosystems, and nutrient or sediment inputs needed for the high biological productivity of estuaries. G. Likelihood of Reservoir Stratification 7. Stratification in a reservoir occurs when the lakes upper zone (epilimnion) is thermally divided from the deeper zone (hypolimnion) the last mentioned becomes stagnant and lacking in dissolved oxygen (anaerobic), thereby undesirable for most aquatic life. A rapid estimate of stratification tendencies in a reservoir can be obtained with the Densimetric Froude Number (F). F can be calculated as F = 320(L/D)(Q/V), where L = length of the reservoir (meters), D = mean reservoir depth (meters) (for which dam height can be a proxy), Q = mean water inflow (cubic meters per second), and V = eservoir volume (cubic meters). If F is less than 1, some stratification is expected, the severity of which increases with a smaller F. When F is greater than 1, stratification is not likely. H. Useful Reservoir Life 18. Useful reservoir life is the expected number of years before a reservoirs dead storage is completely filled, so that further sedimentation reduces the live storage and curtails power generation. Dead storage comprises all reservoir water beneath the level of the intakes for the dams turbines all of the water at or above this intake level is part of the live storage.Useful reservoir life is a function of dead storage and river-borne sediment loads. Useful reservoir life is a good indicator of the relative sustainability of electric power generation it varies from less than ten years before dead storage is filled (su ch as the Paute Dam in Ecuador) to potentially thousands of years. In general, reservoirs with the longest useful life are relatively deep and situated on rivers with low sediment loads. Maintaining low sediment loads over time typically requires good watershed management. Good Dams and Bad Dams 11 I. Access Roads through Forests 19.Where the risks of induced deforestation are high, project siting should minimize the kilometers of required new or upgraded access roads passing through or near natural forests. J. Persons Requiring Resettlement 20. The number of people physically displaced by hydroelectric projects ranges from home in (e. g. Pehuenche, Chile) to over 50,000 in Latin America (e. g. Yacyreta, Argentina-Paraguay) and well over 1 million in Asia (Three Gorges, China). Dam siting should generally seek to minimize the number of individuals or households requiring resettlement from lands affected by the reservoir and complementary civil works.A useful measure for relating re settlement costs to hydropower benefits is the ratio of people displaced per megawatt (Table 2). Because of their usually greater vulnerability to social disruption, it is especially important to minimize the number of indigenous people with traditional land-based models of production who would require resettlement. K. Critical Natural Habitats Affected 21. It is important to know the number of sites and hectares of critical natural habitats that would be lost to inundation, borrow pits, or other project components.Critical natural habitats include existing and officially proposed protected areas, as well as insecure areas of known high importance for biodiversity conservation. To comply with the World Banks Natural Habitats Policy, hydroelectric projects should not cause any significant loss or degradation of critical natural habitats. On the other hand, some hydroelectric projects imply very important conservation opportunities by providing a strong justification (sediment reduct ion) and financial resources needed for protecting natural habitats in upper catchment areas.L. Fish Species Diversity and Endemism 22. Fish species diversity is the number of species known from the project area, including the dam and reservoir site, as well as the downstream zone of project influence. Fish species endemism is the number of native species known only from the project area, or the river system where the project is located, and nowhere else on Earth. Dams are environmentally less objectionable if they affect rivers with a naturally low diversity and endemism of native fish species.In general, large, sea-level rivers in warm (tropical or subtropical) climates have a high diversity of native fish and other aquatic organisms, while small rivers in cold (tropical mountainous or temperate) climates have relatively low diversity. Large, lowland rivers are also more likely to have significant seasonal worker fish migrations, which are effectively blocked by most dams. Howev er, highland rivers and streams often have relatively high endemism in their fish fauna, especially if they are isolated from other rivers by waterfalls or other natural barriers.River segments with threatened fish species found nowhere else should be sort out as critical natural habitats and, ideally, would receive permanent protection from dams or other potentially damaging civil works. However, dams and reservoirs in upper tributary rivers and streams need not threaten the survival of any endemic fish (or mollusks, or other aquatic life) if they affect only an insignificant portion of the river area used by these species (see Indicators D and E) they should also be sited so as not to block important fish migrations. M. Cultural attribute Affected 23.An indication of the cultural significance of the area to be inundated (or otherwise affected by the project) is the number (by type) of cultural (archaeological, historical, paleontological, or religious) objects or sites. It is imp ortant to note whether each type of cultural property at the project site is salvageable (totally, partially, or not at all). 12 LCR Sustainable Development Working Paper No. 16 Table 2. Land Area Flooded and People Displaced in Large Hydropower Projects Project (country) Arun II (Nepal) Pehuenche (Chile) Pangue (Chile) Guavio (Colombia) Tehri (India) Ghazi Barotha (Pakistan)Nam Theun-Hinboun (Laos) Ertan (China) Fortuna (Panama) Chixoy (Guatemala) Grand Coulee (United States) Three Gorges (China) Tarbela (Pakistan) Salvajina (Colombia) Zimapan (Mexico) Itaipu (Brazil/Paraguay) Victoria (Sri Lanka) Kararao/Belo Monte (Brazil) Aguamilpa (Mexico) Betania (Colombia) Urra I (Colombia) Mangla (Pakistan) Bakun (Malaysia) Ataturk (Turkey) El Cajon (Honduras) Ilha Solteira (Brazil) Guri Complex (Venezuela) Salto Grande (Argentina/Uruguay) Nam Theun II (Laos) Arenal (Costa Rica) Yacyreta (Argentina/Paraguay) Tucurui (Brazil) Narmada Sagar (India) Porto Primavera (Brazil)Churchill Falls (Cana da) Khao Laem (Thailand) Kedung Ombo (Indonesia) Kainji (Nigeria) Pak Mun (Thailand) Cabora Bassa (Mozambique) Aswan High (Egypt) Nam Ngum (Laos) Sobradinho (Brazil) Kariba (Zambia/Zimbabwe) Balbina (Brazil) Akosombo (Ghana) Bayano (Panama) Kompienga (Burkina Faso) Brokopondo (Suriname) Installed capacity (MW) 402 500 450 1,000 2,400 1,450 210 3, three hundred 300 300 6,494 18,200 3,478 270 280 12,600 210 8,381 960 510 340 1,000 2,400 2,400 300 3,200 10,300 1,890 1,086 157 3,100 3,980 1,000 1,815 5,225 300 29 760 34 2,075 2,100 150 1,050 1,260 250 833 30 14 30 Reservoir rea (hectares) 43 400 500 1,530 4,200 2,640 630 10,100 1,050 1,400 33,306 110,000 24,280 2,030 2,300 135,000 2,270 116,000 13,000 7,370 7,400 25,300 70,000 81,700 11,200 125,700 426,000 78,300 45,000 7,000 165,000 243,000 90,820 225,000 665,000 38,800 4,600 126,000 6,000 380,000 400,000 37,000 415,000 510,000 236,000 848,200 35,000 20,000 160,000 People displaced 775 0 50 4,959 100,000 899 0 30,000 446 3,445 10,000 & gt1,300,000 96,000 3,272 2,800 59,000 45,000 n. a. 1,000 544 6,200 90,000 9,000 55,000 4,000 6,150 1,500 n. a. 5,700 2,500 50,000 30,000 80,500 15,000 0 10,800 29,000 50,000 4,945

Moral Law in Trifles

Throughout story it is shown that wo custody have been smellinged voltaic pile upon by men. They have been considered inferior to the opposite agitate and even as a form of property. Trifles take place in 1916 where the rights of women ar yet to be stated a place that is rule by the paterfamilias, the men. Only men knew what was right, only men knew what was best for their families. hands criticized women a lot and made fun of them.Men do not date the difficulty of these duties and the hard working hours that are needed to keep a farmhouse and or a family tidy and well organized. Women just make their lives look easier by cooking, cleaning and caring for their children. Although today, we are not burdened with this seek of being physically and emotionally abused by men, women in the early(a) 1900s struggled to break free from this mold formed by society.In the Trifles this suit of living made lively, singing, happy Minnie Wright turn into a mentally disturbed, crisp and routine robot after she married her husband, Mr. Wright. However, in the play women are far from being decorative. They actually show greater strength than the ring men. As the men went upstairs to investigate what happen to the husband, the women stays down stairs. They were competent to look at the scene and pay attention to the expand which lead them to uncover the clues that Mrs.Wright murdered her husband. At that time before the men came downstairs, the women hid the evidence and did not judge Mrs. Wright for her action. I can only place that moral justice prevailed and that law should not be so harsh in some cases because there are more psychological aspects in a human mind. The women hid the evidence as an act of compassion for Mrs. Wright. stealth the box with the dead bird is an act of loyalty to their gender and of defiance against a callous patriarchal society.A murder case like this at that particular time was a shocking thing to solve because it snarly tiny deta ils that men could not understand or make without the help of women. Details that are presented in women lifestyle, Mrs. Peter and Mrs. Hale was able to relate to Mrs. Wright to the murder of the killing of her husband. This conflict is the moral justice versus the levelheaded justice meaning that justice can be based on what somebody conscience suggest what is right or wrong, rather than on what that strict law says to be done.Although Mrs. Peters was hesitating about the decision of secrecy the evidence, she knew it was the right thing to do. The women understood the moral law and the Sheriff Hale and the County attorney represented legal justice. In this world women have always been set second best by men and like they were never serious enough for careers outside of the home. The sex of a person should not determine what type of job a person should have. Due to those facts the women in Trifles stood by each other to cover Mrs. Wright tracks

Individual Optimism and Health

Iris Hobnobs Optimists take proactive steps to protect their strong-arm and mental wellness as thoroughly as focusing on goals that benefit their socioeconomic standing. The trait of optimism whitethorn provide cognitive, coping, and contextual resources that promote damp mental health (Carver, et al. , 2010. P. 880 up. 2). Optimism is a behavioral trait that describes people who look for the validatory in a situation. Optimism can help people cope in invalidating situations and three to greater well-being.Optimists ability to cope with shun situations gives them increase opportunity to accompany and live healthier lives, compared to pessimists, be shake up they believe a positive result is to a greater extent likely. Comparatively, optimists should be measured the same against pessimists on a scale of precise pessimistic to very optimistic with the majority of people falling somewhere in the middle (Carver, et al. , 2010). People display varying degrees of capability when c onfronted with positive and proscribe situations and tend to react based on their acquired behavior.Past experiences can mask the espouse of a individual to either pessimism or optimism depending on whether the cause was permanent or temporary (Peterson &038 Salesman, 1984). How a someone responds can work the ultimate subject of a situation whether it pertains to physical or mental health. Psychologically, optimists seek a positive outcome in the face of prejudicial causes or conditions that range in influence anywhere from benign to malignant.A somebody dealing with a stressful situation There are obsolete instances in which optimists fall short on their ability to overcome a negative tuition, which are mostly discounted due to the specificity of situations. For example, if a pregnant sustain is optimistic about the health of her baby but has a still get despite her positive attitude. A mothers optimism for her childs health did non influence the fortuity of a miscarr iage and left her especially vulnerable because she had not fain herself to deal with the possible negative outcome.This situation is uncommon because the prevalence of aesculapian assistance in most industrialized nations supports an optimistic viewpoint for the birth of a healthy child. Past causes that oblige a persistent negative effect can influence a person to think pessimistically because the stability of negative effects increases the likelihood of a perceived negative outcome. Conversely, temporary negative effects can influence a person to think more optimistically because the negative effects do not have a strong enough correlation with the perceived outcome (Peterson &038 Salesman, 1984).The idea that everything provide turn out all right in the end removes a persons need to analyze potential negative conditions due to the ultimate positive outcome. By not focusing on the potential negative conditions, the level of distress experienced during negative situations is decreased, in like manner fostering proceed dispositional optimism. Therefore, optimism is seen as an acquired behavioral trait and coping mechanism and can be taught to pessimists to meliorate their well-being.Patients with terminal illnesses whitethorn overlook the negative conditions of their illness by emphasizing the positive conditions with dispositional optimism. Researchers have also found that a person with dispositional optimism can positively influence heir physical recovery or management of life-threatening illnesses, such as cancer or HIVE, because the increased capability minimizes the level of distress they experience and allows them to use additional corporate resources toward recovery. The general line of thinking underlying this research is that optimists may be less reactive than pessimists to the stresses of life the lower physiological stress responses may (over many years) result in less physical wear and pull on the body the end result may be better physi cal health and even greater longevity (Carver, et al. 2010. P. 883 up. 13). Optimists are also less likely to engage in activities that can harm their physical health or develop harmful habits and addictions, such as consume and drinking.Engaging in physically harmful activities can be seen as an outpouring mechanism (Carver, et al. , 2010) in response to conditions or experiences that the person feels are in addition stressful to cope with or overcome. In moderation, these activities may not have a direct influence on a persons immediate physical health but can foster behavior that increases the risk of proceed harmful activities. Smoking one cigarette can make a person feel more relaxed and may not seriously assume their health, but smoking every day increases the risk of serious health problems with little prospect of physical recovery.Optimism can foster behavior that benefits a persons well-being, psychologically and physically. It allows a person to overlook or cope with emotionally stressful situations despite the negative circumstances and see an outcome to which they will ultimately benefit. A person with dispositional optimism also shows a motivation toward goals that emend physical health and a decrease in the level of participation in activities that might be harmful.Optimism is a behavioral trait that does not have to be inherited and can be taught to anybody that wish to improve their well-being.

Persuasive Communication Theory

telling conversation shrink fromjecture in kindly Psychology A Historical Perspective Icek Ajzen University of Massachusetts Amherst From M. J. Manfredo (Ed) (1992). Influencing homophile Behavior system and Applications in Recreation and Tourism (pp 1 27). Champaign, IL Saga a neat deal Publishing. glib-tongued Communication system summon 1 well-nigh subjects in amicable psychology crap attracted as much please and circumspection as convincing communicating. One of the first topics to be systematic solelyy investigated, cerebration has been the focus of intense question efforts throughout much of friendly psychologys brief scientific history.Untold experiments charter been conducted to unravel the intricate web of detailors that come out of the closet to playfulness a post in determining the efficientness of a glib inwardness. These try outs present revea direct a stratum of complexity that turn overms to defy commentary and that poses serious obstacles to system construction. However, upstart years fork up seen massvasable expire at the theoretical level and a resurgence of empirical ask believe has d unrivaled much to invigorate the field and father home the bacon a come apart to a depresseder placestanding of the fundamental psychological routinees downstairslying thinking.To appreciate the signifi poopce of these developments we moldinessiness compargon the emerging ideas and research findings with those from earlier efforts. The posture chapter is designed to mastervide the implored historical perspective. Since it aims to re mint developments in our netherstanding of the intellection military operation, vehemence is placed on ideas and theories rather than on methodological or serviceable concerns empirical research findings atomic enumerate 18 summarized to a greater expirationover in broad describe when needed to call for a orient of theoretical significance.The solution of problem s created by recreation and tourism often involves panorama in whizz melodic line or an round a nonher(prenominal). As the chapters in the second part of this book illustrate, recreationists moldiness be persuaded to observe rules of safety, to avoid conflicts with other visitors, and to keep their regard on the environment to a minimum. Although societal psychologists have rarg solitary(prenominal) tested their ideas in the mise en scene of recreation and tourism, the findings and conclusions discourseed down the stairs have obvious implications for any act to peg down tactile sensations, perspectives, and mien in this cosmos.THE NATURE OF vox populi glib talk involves the use of verbal inwardnesss to fix berths and behavior. Although the background of judgement moldiness needs be considered, the verbal pass along, designed to sway the hearts and minds of the receiving systems, is at the substance of cogent communication. Through a puzzle out of conclude, the contentedness exerts its influence by force of the rivalrys it contains. As we shall see below, this emphasis on reasoning sets glib-tongued communication apart from other social influence strategies.Structure of a centre As a general rule, a gist consists of three split An advocated send, a set of general melodic lines in survive of the advocated berth, and specific literal evidence designed to bolster the general accounts (Fishbein and Ajzen, 1981). The advocated pip whitethorn be a stand on a particular issue (e. g. , substantiate for a tax increase) or a recommended action (e. g. , donating blood). The general arguments pull up s rams typically supply reasons for collecting the advocated aspect, and justification for the arguments is provided in the general anatomy of factual evidence.Consider the apparent movement of instituting a senior comprehensive tryoutination for undergraduate college students. superficial and Cacioppo (1986, pp. 54-5 9) make whatsoever examples of general arguments and musical accompanimentive evidence they have apply in their research program. Among the major(ip)(ip) arguments contained in minuscule and Cacioppos contentednesss were the claims that instituting a comprehensive exam inflames students grade point averages and leads to improvement in the quality of undergraduate teaching. The factual evidence in support of the first argument was formulated as follows (pp. 4-55) The National Scholarship Achievement calling card youngly revealed the results of a five-year piece of work conducted on the arrangeiveness of comprehensive exams at Duke University. The results of the try showed that since the comprehensive exam has been introduced at Duke, the grade point average of undergraduates has increased by 31%. At comparable schools without the exams, grades increased by whole 8% over the same period. The prospect of a comprehensive exam chokely seems to be hard-hitting in challengi ng students to work harder and faculty to teach more trenchantly.It is probable that the benefits observed at Duke University could in like manner ingratiatory Communication opening Page 2 be observed at other universities that adopt the exam policy. If original as valid, the factual evidence should result in acceptance of the argument that instituting a senior comprehensive exam testament raise grade point averages, and acceptance of the argument in free rein should increase the likeliness that teleph ace recipient roles will endorse the position in prefer of instituting a comprehensive exam, as advocated in the subject matter.Thither is, of course, no assurance that receivers of a sum will in fact accept the arguments and evidence it contains. On the contrary, identifying the factors and conditions that produce acceptance of randomness contained in a message is the major purpose of feeling theory and research. Alternative Influence Strategies In put in to develop a punter understanding of the nature of vista, it is instructive to secern persuasion with a a fewer(prenominal) alternative influence strategies. The re shot offered here(predicate) is far from exhaustive but it will help noble blowzy some faultfinding aspects of telling communication.Coercive legal opinion masses can be bring forth to behave in a prescribed way by oblation a sizable reward for observe or by grim severe punishment for non conformity. This strategy of tilt can be rattling good in producing the desired behavior, but its authority is depending on(p) on supervision (French and Raven, 1959) and has few lasting cause on tenets or attitudes. unever-changing attitude switch by style of coercion is more likely in the place setting of total institutions, such(prenominal) as prisons, mental hospitals, or prisvirtuosor-of-war camps.Situations of this pleasing enable control over umteen aspects of an individuals life for an all-embracing period of t ime. Even here, however, digest attitude change is difficult to attain and often fades after release from the institution (see Schein, 1961). Hypnosis and Subliminal Perception sort of of trying to overtake safeguard to change by force of coercion, one can attempt to circumvent conscious opposition by federal agency of hypnosis or insertion of subliminal messages. Posthyp nonic induction can be used to instruct individuals upon awakening to engage in specified behaviors or to represent newly attitudes (e. . , Rosenberg, 1956). There is, however, some question as to whether hypnosis actually represents an altered call forth of consciousness that can be used to circumvent peoples coarse resistance to manipulation of their views and actions (cf. Barber, 1965 Wagstaff, 1981). Use of subliminal cognizance to bring close to change is correspondently problematic. Its effectualness depends on the presentation of training at an intensity level too low for conscious percepti on, yet high generous for it to enter unconscious or subconscious sensory faculty.Clearly, such a fine balance demands protective(predicate) calibration and, passing(p) individual differences in perceptual acuity, whitethorn non be achievable in a mass communication context. In any as yett, up to now when subliminal perception can be demonstrated, its cause on attitudes and behavior tend to be of rather small magnitude (cf. Erdelyi, 1974). Conditioning and Affect Transfer some other way of trying to avoid resistance to change involves the use of instruct procedures. It has been argued that attitudes can be changed by means of classical conditioning (e. . , Staats and Staats, 1958) and that behavior can be influenced through the systematic use of reinforcements in an implemental conditional paradigm (e. g. , Krasner, 1958). Since the returns of conditioning in comparison to aspire persuasion rests on the false cap talent of conditioning to operate without advisednes s of the influence attempt, the extent to which individuals submitted to conditioning form hypotheses closely systematic associations created in the conditioning paradigm is of crucial importance. contradictory to earlier claims, it now appears that at that place is no convincing evidence that adult human beingnesss can be well-educated without awareness (cf. Brewer, 1974). An idea related to classical conditioning has emerged in the recent marketing literature where it has been proposed (Batra and Ray, 1986 Mitchell and Olson, 1981) that positive or negative affect kindle by one excitant (the advertising) can transfer automatically to an associated stimulus (the advertised deformity). This Persuasive Communication Theory Page 3 ffect transfer, however, is assumed to pass only when individuals have no other, more cognizant basis, for evaluating the brand in question (Shimp, 1981). Moreover, regressn the results of research on conditioning in human beings, it can be assumed that affect transfer, if it occurs at all, occurs only in the presence of awareness of the contingencies involved. Subterfuge obvious heuristic in a persuasion context has to do with the communicators believ king. The position advocated in a message may be accepted if the message comes from a exceedingly credible quotation but rejected if the start is perceived to wish credibility.When using this rule of thumb, receivers accept or reject the advocated position or action without considering the merits of the arguments contained in the message. Conclusions Whereas the strategies discussed consequently far all in one way or another try to prevent or ravage awareness of, and thus resistance to, the influence attempt, the strategies considered here subtly talk through ones hat the situation in order to promote a psychological state that leads people voluntarily to engage in the desired behavior.The foot-in-the-door technique (Freedman and Fraser, 1966) and other sales ploys are good examples of this approach. When using the footin-the-door technique, a small put across SQ acceded to by some individuals SQ is followed by a much declamatoryr postulate. receivable presumably to the commitment produced by agreeing to the small request, conformity with the large request tends to increase. An alternative strategy involves first confronting a person with an unreasonably large request and then appearing to compromise by offering compliance with a smaller request.In a extremely readable book, Cialdini (1988) describes a subprogram of ways in which subterfuge of this kind can be sedulous to elicit behaviors that cogency otherwise not be performed. Subterfuge strategies take advantage of peoples mingled needs to reciprocate any favor legitimate, to be liked by others, to be coherent, and so forth. Compliance is secured without the benefit of discussing the merits or costs of the requested action. heuristics We have noted that change by means of ingrat iatory communication is based on a careful ineptness of the pros and cons associated with an advocated position or ction. We shall see in subsequent instalments, however, that receivers of a message sometimes make judgments about the advocated position without leaving through an enlarge reasoning butt. Instead, they may rely on heuristics or rules of thumb to pay back at a conclusion (cf. Chaiken, 1980, 1987). The close to Our treatment shows that social influence can operate in a variety of ways and that various strategies are available to take advantage of the divergent possibilities. Nevertheless, persuasive communication occupies a unique position in the matrix of social influence.Of all the available strategies it is the only one that appeals to reason, attempting to bring about change and compliance by convincing the individual of the validity or legitimacy of the advocated position. This tactical maneuver can be much more difficult than, hypothesise, coercion, but it overly has essential advantages. Besides being more compatible with democratic and humanitarian values, persuasive communication can produce pro name and lasting change, a remnant not easily attained by other means. THE PERSUASION CONTEXT No message appears in a vacuum.At a minimum, we can usually identify the root of a message an editor of a newspaper editorial, a lawyer pleading a clients case onwards a jury, or a movie star asking for donations to a charity. The communicators identity, however, is only one of the many an(prenominal) factors that constitute the context of persuasive communication. undefiled analysis (Lasswell, 1948) has divided communication into several distinct aspects that can be summarized as who says what, how, and to whom. More formally these aspects are know as source, message, express, and receiver factors together, they constitute the context of 1 persuasion.Source Factors Source factors are observed or inferred characteristics of the communic ator. They imply biological attributes such as age, race, height, and sex behavioral features such as Persuasive Communication Theory Page 4 seventh cranial nerve expressions, mannerisms, hand and body movements, and the way the communicator is dressed social properties such as income, power, and social status and personality traits such as self-confidence and extraversion. The around frequently studied source factors, however, are the communicators credibility and force card.Credibility refers to the perceived expertise and trus dickensrthiness of the communicator. In other words, does the communicator have the knowledge to provide an informed opinion on the issue in question and, if so, can he or she be trusted to present all relevant breeding in an unbiased fashion? As noted earlier, persuasion is generally assumed to increase with credibility. It has similarly been proposed that the amount of change is influenced by the attractiveness or likability of the source, whether attractiveness is defined in terms of physical features or psychological and behavioral characteristics.Receiver Factors On the opposite end of the communication context, correspond to source factors, are characteristics of the receiver or audience to whom the message is addressed. These characteristics include the receivers personality traits, sex, social status, intelligence, participation, and so forth. Any attribute of the audience, or faction of attributes, may provide a context that contributes to the effectiveness of the message. Channel Factors The context of the message is also defined by the means used to guide it.Information can be communicated face-to-face, in writing, or by way of an strait tape or video tape. Note that although it is accomplishable to hold the content of the message (the general arguments and factual evidence) constant across ravishs, polar modes of communication will often vary in terms of some of the context factors. For instance, the audie nce obtains more study about physical and behavioral characteristics of the source from face-to-face or video messages than when the teaching is presented in written or oral form.Thus, it may be difficult in some instances to determine whether differences in persuasion are due to variations in the communication channel or to associated contextual differences that may con appoint the observed effect. Message Factors potency con shewing of a more serious kind can occur in the case of message factors because variations message features are often go with by differences in content. Message factors concern the ways in which development is communicated to the audience.Among the factors that have been considered are the order in which arguments are presented, one- versus deucesided presentations, and emotional versus nonemotional appeals (e. g. , hilarious messages or messages that arouse timidity versus neutral messages). To see why variations in message characteristics are often c onfounded with differences in message content, consider the case of one- versus two-sided communications. Clearly, to present both sides of an issue, an effective message must contain information and arguments not contained in a message that supports only the advocated position.In a twosided message, the communicator mentions arguments that could be used to support the opposite side and then proceeds to refute those arguments. In addition, of course, the communicator also discusses the arguments in favor of the position advocated in the message. Only this part is the same as or similar to the one-sided message. In the case of emotional versus neutral appeals, problems of confounding occur because desireous or fear-arousing communications generally contain information and arguments specifically designed to generate these emotions.It is thus difficult to separate the effectuate of fear or humor from the effects due to differences in the information contained in humorous versus non humorous messages or in high- versus lowfear messages. Situational Factors The persuasion context contains several situational variables that do not fit easily into the customsal framework of source, message, channel, and receiver factors. Among these situational variables are bewilderment and forewarning. Distraction can be the result of environmental noise, or it can be internal as when a person is preoccupied with other concerns.Forewarning refers to the availability Persuasive Communication Theory Page 5 of information before expo convinced(predicate) to the message, which warns the receiver both that an influence attempt is imminent or that the communicator is planning to advocate a certain position. In either case, forewarning may prepare receivers to rally their defenses over against the forthcoming message. The Hovland impost Scientific work on persuasive communication began in keen during World War II in an attempt to determine the effects of war-time propaganda (Hov land, Lumsdaine, and Sheffield, 1949).This was followed by a period of intensive observational research at Yale University in the 1950s under the focusing of Carl Hovland (Hovland, Janis, and Kelley, 1953 Sherif and Hovland, 1961). Although it was extremely prolific and highly influential, the program of research initiated by the Hovland classify produced actually few generalizable conclusions. By the late 1960s, disappointment with this approach had become widespread (see Eagly and Himmelfarb, 1974 Fishbein and Ajzen, 1975). In this section we re fascinate the major lines of work in the Hovland tradition and consider some of the reasons for its trouble.Theoretical Orientation The empirical work of the Hovland group was guided by a loose theoretical analysis based on need principles, and by a conceptual framework that incorporated context variables (source, message, channel, and receiver factors), localize variables ( flying attitude change, retention, behavior change), and mediating processes (attention, comprehension, and acceptance) (see McGuire, 1969, 1985). Very briefly, the theoretical analysis assumed that attitude change involves learning a new response to a give stimulus (the attitude object).Exposure to a persuasive message suggests the new response (the advocated position) and provides an opportunity to practice the response. The various contextual factors were assumed to drive learning by reinforcing and firmly embedding the new response in the receivers response hierarchy. data-based Research The conceptual framework of context, arse, and mediating variables served to organize thinking about the persuasion process. However, much of the empirical research in the Hovland tradition dealt primarily with the allude of contextual factors.Thus, in the 1950s and 1960s, hundreds of studies were conducted to examine the effects of source credibility and attractiveness receiver intelligence, egoism, and involvement fear appeals and order of pr esentation beguilement and forewarning and a multitude of other contextual variables (see McGuire, 1985 for a recent review). Little attention was devoted to the dependent variable that serves as the target of the communication, although persistence of change over time was an early concern (see manage and Flay, 1978). Of the mediating variables, only attention and comprehension were at present assessed.Thus, many studies contained a disown or re acquaintance test to measure the degree to which the message was received (McGuire, 1968), that is, the degree to which the message was attended to and comprehended. Generally speaking, the purpose of the test was to make sure that reaction did not vary across conditions of the experiment, and that whatever effects were observed could not be attributed to differences in reception. In other words, the goal was usually to rid the experiment of the mediating effect of reception, rather than to study reception in its own right.Note also that the conceptual framework had teensy to say about the content of persuasive communication and what its role in the persuasion process might be. Message content was treated largely as a given, while the questions addressed had to do with the effects of contextual factors on the amount of change produced by the message in question. We shall see below that this approach to the study of persuasive communication was one of the major reasons for the crackure of the Hovland tradition. Effects of source factors.One of the first lines of research initiated by the Hovland group dealt with the effects of communicator credibility (Hovland and Weiss, 1951), and innumerable studies since have manipulated this variable. Of all the contextual factors studied in the Hovland tradition, variations in source credibility have produced the most consistent findings. By and large, communicators high in expertise and trustworthiness tend to be more persuasive than communicators with low standing on these f actors. However, even here, somePersuasive Communication Theory Page 6 contradictory evidence has been reported. Source credibility does not always increase the amount of change, and in some situations it can even have a negative effect (cf. McGuire, 1985, p. 263). Other source characteristics are generally found to have no guileless or easily predictable effects on persuasion. The communicators attractiveness, education, intelligence, social status, and so on can serve as cues for inferring expertise and can thus affect persuasion.However, these confirmatory effects do not appear to be muscular enough to produce consistent results across contrastive investigatings. Effects of receiver factors. Age, gender, intelligence, self-esteem and other individual differences among receivers are rarely found to have tough effects on persuasion, and the results of diverse investigations are often inappropriate. Moreover, receiver factors are found to interact in complex ways with each o ther and with additional factors such as the complexity of the message, the subject of arguments used, the credibility of the communicator, and so on.Effects of channel factors. A rather discouraging picture also emerged with respect to the effects of the medium of communication. While visual messages tend to be better liked and attended to than spoken or written messages, recall is sometimes better for written material, and adding pictures to print can be distracting (see McGuire, 1985, p. 283). In light of these contradictory effects, it is hardly surprising that empirical research on channel factors has produced largely ill-matched results.Effects of message factors. well-nigh of the most complex blueprints of findings are associated with message factors such as emotional versus nonemotional appeals, message style, and ordering of message content. With respect to the latter, consider for example whether one should state the messages basic position at the outset or at the end. Stating it at the beginning may have the advantage of clarity, making the source appear more trustworthy, and of attracting the attention of receivers sympathetic to the advocated position.It can also have the disadvantage, however, of lowering wager and antagonizing receivers ab initio opposed to the advocated position (McGuire, 1985). Other message factors can have evenly complicated effects. To illustrate, consider the degree to which the message arouses fear or concern. Contrary to gestateations, initial research (Janis and Feshbach, 1953) showed a low-fear message to be more effective than a high-fear message in producing compliance with recommended dental practices.Later research, however, has often found the opposite effect, and many investigations have reported no differences between high- and low-fear messages (for reviews, see Boster and Mongeau, 1985 and Higbee, 1969). Similarly inconsistent findings have emerged with respect to the effects of humor in persuasive com munication (see Markiewicz, 1974). Retrospective In light of largely inconsistent research findings concerning the effects of contextual variables, many investigators became discouraged with the Hovland approach.Thus, after redaction a book on attitude change in 1974, Himmelfarb and Eagly reached the undermentioned pessimistic conclusions After several decades of research, there are few simple and direct empirical generalizations that can be made concerning how to change attitudes. In fact, one of the most prominent features of recent research is the great tote up of studies demonstrating that the empirical generalizations of earlier research are not general, but contingent on conditions not originally apparent. (Himmelfarb and Eagly, 1974, p. 94. ) In fact, the complexity of the persuasion process noted by Himmelfarb and Eagly in their reference to contingencies has been a favorite explanation for the failure of the Hovland approach. This explanation holds that persuasion is in fluenced by so many different factors interacting with each other that only complicated, multidimensional research strategies can come with the complexities. However, when investigators have studied higher-order interactions, no clear or replicable patterns have emerged.Indeed, there is serious doubt that the search for complicated interactions can ever be a viable strategy (cf. Cronbach, 1975 Nisbett, 1977). The role of the receiver. Besides failing to set ahead our understanding of the persuasion process, the complexity explanation had the Persuasive Communication Theory Page 7 unfortunate effect of hiding the basic shortcomings of the Hovland tradition and thus delaying the search for alternatives. As is usually the case, realizing where this approach went wrong is much easier in retrospect than it was at the time.Perhaps without meaning to, the Hovland group cast the receiver in a rather passive role whose task was to learn the information and recommended position presented in a message. Attention and comprehension would retard that the information was absorbed, and persuasion would thus follow automatically. This view of the receiver stands in clear contradiction to much that is known about information processing. People are far from passive receivers of information.Instead, they usually act on the information that is available, integrating it (Anderson, 1971), constructing interpretations of their own (Neisser, 1976), and going in many ways beyond the information given (Bruner, 1957). This is just as true in the domain of attitudes as it is in other areas of information processing. For example, research on apprehension formation has shown that people draw far-ranging inferences about the attributes of another person on the basis of very limited information (Asch, 1946 Fishbein and Ajzen, 1975 Wiggins, 1973).Such inferences are often verbalise to rely on implicit theories of personality (Schneider, 1973) which might suggest, among other things, that if a person is said to be hostile, he is also likely to be rash, aggressive, and inconsiderate. Several other lines of research demonstrate more directly the potential drop importance of inference processes in persuasive communication. Thus it has been shown that a persuasive communication designed to produce a change in one stamp will also lead to changes in other, related, beliefs (McGuire, 1960a Wyer and Goldberg, 1970).It is even possible to produce change by merely making people aware of inconsistencies among their beliefs or values (McGuire, 1960b Rokeach, 1971) in a process McGuire has termed the Socratic effect After reviewing their beliefs, people tend to change some of them in the direction of increased logical consistency. In short, there is every reason to expect that receivers exposed to a persuasive communication may engage in an active process of deliberation that involves reviewing the information presented, accepting some rguments, rejecting others, and drawing in ferences about issues addressed that go beyond what was mentioned in the original message. The enter of the passive learner fostered in the Hovland tradition is thus highly misleading, and misses the most important aspect of persuasive communication the receivers capacity for reasoning and for being swayed by the merits of a well-presented argument. thought process by the Peripheral Route The passive-learner view of the receiver implicit in the Hovland approach quite naturally led to a focus on the persuasion context.If the communicators task is to make sure that receivers learn and absorb the contents of the message, concern turns to a search for conditions that facilitate attention to the message and comprehension of its arguments, with a concomitant lessening of interest in what the receiver does with the information that is received. Ironically, recent theory and research have established the potential importance of contextual factors, at least under certain wellspecified con ditions. Once we realize what these conditions are, we can begin to understand the reasons for the inconsistent findings of research conducted within the Hovland paradigm.In the previous section we emphasized the active role of the receiver who may engage in an elaborate process of reasoning about the merits of the arguments presented in the message. This view assumes, first, that receivers are in fact sufficiently motivated to exert the required cognitive effort and, second, that they have the ability to carefully process the incoming information. It now appears that contextual factors influence persuasion only when one or both of these conditions are not met (Chaiken, 1980 Petty and Cacioppo, 1981, 1986).Motivation to process the message and elaborate on it is largely a take of the receivers involvement. divers(prenominal) aspects of the self may be activated in a given situation, depending largely on the issue addressed, and as a result, different kinds of involvement can be ge nerated. Specifically, the message may create involvement by dealing with receivers enduring values, with receivers ability to obtain desirable outcomes or avoid undesirable outcomes, or with the impression receivers make on others Persuasive Communication Theory Page 8 (Johnson and Eagly, 1989).However, when the message has few implications for enduring values, for important outcomes, or for selfpresentation, it produces little motivation to carefully deliberate its contents. top executive to process a message is related to factors internal to the receiver as well as to external factors. Among the internal factors are familiarity with the issues and cognitive ability and intelligence, factors that tend to increase capacity for information processing and preoccupation with other matters and privation of time, which tend to reduce the ability to elaborate.External factors that increase the ability to process include message repetition and clarity of presentation, while external dis traction and use of complicated language can reduce processing ability. Some of the contextual factors studied by the Hovland group can come into play when internal or external factors lower the receivers ability to process the information presented in the message. Empirical Research When ability and motivation to process the message are low, receivers can use skirting(prenominal) cues (Petty and Cacioppo, 1986) or cognitive heuristics (Chaiken, 1980) to form their opinions.Chaiken assumed that receivers of a message, even if they are not very greatly involved, nevertheless are motivated to hold a correct view on the issue. Since, under conditions of low motivation and ability, receivers are either unable(predicate) or unwilling to deal with the merits of the advocated position, they look for contextual or encircling(prenominal) cues that might provide a basis for forming an opinion. Perhaps the most all-powerful such cue is the communicators credibility, and it may be argued th at this is the reason for the relatively consistent findings associated with communicator credibility.The heuristic strategy might in this case involve the side by side(p) line of reasoning If this expert on the matter says so, it must be right. This heuristic appears quite reasonable in that it accepts the position advocated by a credible source, even if one has not carefully scrutinized the arguments presented. Receivers can also use the sources attractiveness, or factors related to the message such as the number of arguments it contains, as peripheral cues. Thus, a message coming from a iked source might be viewed as more trustworthy, and one that contains many arguments (even if specious) might be seen as more reliable than a message that contains few arguments. Note, however, that these rules of thumb are far less convincing as a rational basis for accepting or rejecting an advocated position, and it is perhaps for this reason that factors of this kind often fail to have stro ng or consistent effects on persuasion. In any event, relying on heuristics obviates the need for careful message processing, and at the same time provides a basis for adoption of a position on the issue.Recent empirical research tends to support this view of the peripheral road to persuasion, although some complications have belatedly been noted (Johnson and Eagly, in press). Since minute reviews are available elsewhere (Chaiken, 1987 Petty and Cacioppo, 1986), we limit our discussion here to an example concerning the effects of source characteristics. Recall that communicator attractiveness was one of the source characteristics studied in the Hovland paradigm that did not have a clear and consistent effect on persuasion.If treated as a peripheral cue used only when processing motivation or ability is low, more consistent findings tend to emerge. Attractiveness of the source has been varied by attributing the message to famous versus unknown individuals (Petty, Cacioppo, and Sch umann, 1983) or to a likable versus an closed person (Chaiken, 1980). The investigators also manipulated the degree of involvement and found, as expected, that communicator attractiveness has a significantly greater effect on persuasion under low than under high involvement.Conclusions Work on the peripheral highroad to persuasion suggests that the source, message, channel, and receiver factors studied in the Hovland tradition can indeed influence the effectiveness of a message, but that this is likely to be the case only under conditions of low motivation or low ability to process the message. Such conditions can be obtained in the psychological laboratory that ensures some degree of attention by a captive audience even if the receivers have little interest in the topic or lack the ability to process the information presented (Hovland, 1959).In more naturalistic field settings, receivers who Persuasive Communication Theory Page 9 lack the motivation or ability to process a message can usually farewell the situation, while those who remain and are exposed to the message will tend to be sufficiently involved and able to process the information it contains. Persuasion by the peripheral route is clearly an inappropriate model for many realistic situations, and it is often inapplicable even in the artificial context of the laboratory.REASONING AND PERSUASION Even when it works, there is something distinctly unsatisfactory in the notification of change via the peripheral route, because the change brought about does not represent persuasion as we usually think of it. We noted at the beginning that it is the process of reasoning, the evaluation of the merits of arguments in favor and opposed to the advocated position, that is at the heart of persuasive communication. Persuasion involves more than simply oing along with an expressed point of view because of the presence of some peripheral cue it requires that the advocated position be accepted only after careful sc rutiny of the message and after lotion of whatever other information the receiver can bring to bear. Moreover, change produced by the peripheral route is generally of little practical significance. Petty and Cacioppo (1986) noted that peripheral attitude change tends to be shortlived, tends to be liable(predicate) to counterpropaganda (McGuire, 1964), and tends to have little effect on actual behavior.Clearly then, from both a theoretical and a practical point of view it would be to our advantage to focus less on the context of persuasion and more on the central processes that occur when a person is exposed to a message. Persuasion by the Central Route In the remainder of this chapter we examine persuasion that occurs when the receiver of a message is sufficiently able and motivated to give at least some scrutiny to the contents of the communication and to pass judgment the merits of the arguments it contains.This has been termed the central route to persuasion (Petty and Caciop po, 1981) and the deliberations receivers perform are known as systematic information processing (Chaiken, 1980). Instead of asking what makes a given message more effective, we must now ask how to construct an effective message. That is, what arguments, when systematically processed via the central route, will have the greatest impact on the receivers attitudes and behavior? Before we can review what is known about this question, however, we must consider the role of the receiver in greater detail. The intricacy Likelihood Model.The peripheral route to persuasion discussed earlier is one of two tracks a receiver can take in Petty and Cacioppos (1981, 1986) refinement likelihood model (ELM). The second track is persuasion via the central route. correspond to the ELM, central route persuasion depends on and is determined by the degree to which receivers elaborate on the information presented in the message. Briefly, during exposure to a persuasive communication, receivers are assu med to generate arguments of their own, either in support of the advocated position (pro arguments) or opposed to it (con arguments).These cognitive responses determine the direction and degree of change in attitudes and behavior. Increased motivation and ability to process the information in the message is, consort to the model, associated with an increase in the number of cognitive responses (pro and con arguments) generated. To the extent that the number of arguments generated on the pro side exceeds the number of arguments on the con side, the receiver will change in the advocated direction. When elaboration leads to the takings of more con than pro arguments, however, either no change or a boomerang effect (change in the opposite direction) may occur.From the communicators point of view, therefore, motivation and ability to elaborate on message content is a two-edged sword. If, on balance, the thoughts generated by the receiver favor the advocated position, then the central r oute to persuasion works to the communicators advantage. On the other hand, if the receivers cognitive responses consist preponderantly of counterarguments, then elaboration on message content can be quite detrimental to the communicators purpose.A number of studies, summarized in Petty and Cacioppo (1986), have examined the role of cognitive responses in the persuasion process. In these studies, cognitive responses are kindle Persuasive Communication Theory Page 10 in a free-response format following exposure to the message. The thoughts listed by the receivers are coded as either in favor or opposed to the advocated position, and the number of responses of each type is determined. Results, by and large, support the idea that the production of cognitive responses increases with motivation and ability to elaborate.Moreover, it is also found that changes in attitudes and behavior are consistent with the pattern of cognitive responses that are generated a balance of thoughts in favor of the advocated position tends to be associated with change in the desired direction. 2 Yielding and Impact. stipulation of cognitive responses generated by receivers in the course of exposure to the message is, however, not sufficient to account for observed changes in attitudes and behavior. For change to occur in the central mode, some of the receivers fundamental beliefs and values must undergo modification.Elaboration on the message may in fact lead to changes in cognitive structure, but evidence for the production of pro- or counter-arguments does not, in itself, assure that such changes have indeed taken place. Work on the elaboration likelihood model has focused primarily on cognitive responses to the message and has not dealt directly with changes in cognitive structure. The ideas discussed below are based on other recent work concerning persuasive communication via the central route (Fishbein and Ajzen, 1975, 1981).harmonize to Fishbein and Ajzen, a message can bring ab out changes in a receivers cognitive structure in one of two ways. First, in a process termed submissive, acceptance of arguments presented in the message can produce changes in corresponding beliefs held by the receiver. Consider, for example, a pregnant smoker who initially is not aware that cigarette smoking can adversely affect the health of her unhatched baby. This woman is now exposed to a message containing an argument and supportive evidence that establish the link between smoking and adverse health effects on the fetus.To the extent that the argument is accepted, it produces yielding in the sense that the womans cognitive structure now contains a new belief that corresponds directly to the argument in question. That is, she now believes, as stated in the message, that smoking may have ill effects on her unborn baby. Changes in a receivers chief(a) beliefs, however, can extend far beyond the information directly contained in the message. Such changes that go beyond the information given are termed impact effects.To illustrate, the pregnant woman exposed to the message that smoking can have detrimental health effects on her fetus may infer that she would feel guilty if she did not fracture smoking and that her doctor would want her to quit, even though neither argument was explicit in the message. It is also possible, however, for her to draw inferences that would work against the aims of the communicator. For example, the woman may unexpectedly form the belief that quitting would be even worse than proceed smoking because it would result in overeating.These impact effects can, of course, play a major role in the womans decision to quit or not to quit smoking. Evidence for the importance of considering yielding as well as impact effects can be found in a study on drinking reported in Ajzen and Fishbein (1980, pp. 218-242). Persuasive crinkle The challenge facing a communicator trying to produce change via the central route is to create a message that will originate approbative responses, produce yielding to its arguments, and generate impact effects in unity with the advocated change. rivalrys contained in a message can be considered effective to the extent that they influence the receivers cognitive structure. The essential question, therefore, is what makes an argument effective. In light of the fact that rhetoricians have written about argumentation for over 2,000 years, it is surprising how little empirical knowledge is available about the relative effectiveness of different types of arguments (McGuire, 1985). An analysis of this problem reveals at least three important aspects of an arguments effectiveness novelty, strength, and relevance.Below we discuss each of these aspects in turn. Argument Novelty Persuasive Communication Theory Page 11 An argument contained in a message may well be accepted (i. e. , believed to be true), but if the receiver already held the belief in question before exposure to the message, no change in belief structure would result (Fishbein and Ajzen, 1981). To be effective therefore, an argument contained in a message must not be part of the receivers initial belief system. Some empirical evidence for this marriage proposal can be found in research on group decision making (Vinokur and Burnstein, 1974).In the course of group discussions, members who offer novel arguments in support of a given decision alternative are found to be more influential than members who raise points that are well known to the rest of the group. Argument Strength Besides being novel, an argument must also be strong if it is to sway the receiver to adopt the advocated position. A strong argument is one that tends to produce agreement (positive thoughts) and does not march on generation of many counterarguments (Petty and Cacioppo, 1986). Although it is not clear what makes a strong argument, its strength or weakness can be empirically established.Earlier in this chapter we gave an illustrati ve example of a persuasive argument taken from Petty and Cacioppos (1986) research program. The argument asserted that instituting a senior comprehensive examination would raise grade point averages (see p. xx). This argument and the associated evidence make a strong case for the advocated position. Compare this to the following argument, also designed to generate support for a comprehensive exam. The National Scholarship Achievement Board recently revealed the results of a study they conducted on the effectiveness of comprehensive exams at Duke University.One major finding was that student anxiety had increased by 31%. At comparable schools without the exam, anxiety increased by only 8%. The Board reasoned that anxiety over the exams, or fear of failure, would motivate students to study more in their courses while they were taking them. It is likely that this increase in anxiety observed at Duke University would also be observed and be of benefit at other universities that adopt th e exam policy (Petty and Cacioppo, 1986, p. 57). Although this argument is quite similar in structure to the strong argument presented earlier, it appears to present a much weaker case.In fact, this argument is typically found to generate many counterarguments. Clearly, in order to create an effective message, it is in the communicators interest to spot strong arguments and avoid including arguments that tend to elicit negative thoughts about the advocated position. Argument Relevance Related to the question of an arguments strength is its relevance to the advocated position. An argument may be strong in the sense that it generates few counterarguments and many pro arguments, but if it addresses an issue that is not directly relevant to the advocated position, it may fail to produce the desired effect.This point is often not sufficiently appreciated. enjoin a communicator would like to convince students to attend an anti-apartheid demonstration in Washington, D. C. , and thus expo ses the students to a persuasive message against apartheid in South Africa. Although the arguments contained in the message may be strong in the sense that they are thinkable and generate few counterarguments, the message may not be very effective as a means of inducing students to go to Washington.To make the message more relevant in terms of this goal, one would have to include strong arguments that deal more directly with the advantages of attending the aforethought(ip) demonstration. A relevant argument, then, is one that changes those firsthand beliefs of the receiver that are directly related to the target of the influence attempt, that is, to the attitude or behavior the communicator wishes to affect. Different target variables are based on different primary beliefs, and an effective message must be tailored to fit the target in question.General discussions of different target variables and their respective foundations of primary beliefs can be found in Fishbein and Ajzen (1975, 1981) and in Fishbein and Manfredo (Chapter xx, this volume). It is beyond the scope of this chapter to provide an in-depth review. Briefly, Fishbein and Ajzen distinguish Persuasive Communication Theory Page 12 among beliefs, attitudes, intentions, and behaviors as possible targets of a persuasive communication. To effect a change in any one of these target variables, the message arguments must be directed at the primary beliefs that provide the basis for the target in question.The first step in the construction of a message, therefore, requires a decision about the relevant primary beliefs, a process that cannot be left to intuition but must be guided by a model of the targets determinants. Social psychologists have discussed a variety of approaches to understanding beliefs and attitudes and their relations to behavior, but perhaps the most popular models can be found within the framework of the theory of reasoned action (Fishbein and Ajzen, 1975 Ajzen and Fishbein, 1980) a nd its recent extension, the theory of aforethought(ip) behavior (Ajzen, 1985, 1988).The discussion below considers each target variable in turn however, a full understanding of the process is gained only by considering the relations among the different variables. Changing behavior. According to the theory of reasoned action, many behaviors of interest to social psychologists are under volitional control and, hence, are in an immediate sense determined by the intention to perform the behavior in question. A successful persuasive communication designed to change a certain behavior must therefore contain arguments that will bring about a change in the antecedent intention. The theory of planned behavior oes beyond the question of intended action, taking into account the hypothesis that the behavior of interest may not be completely under volitional control. To be successful, the message may have to provide information that will enable the receiver to gain volitional control and over come potential obstacles to performance of the behavior. A review of evidence in support of these propositions can be found in Ajzen (1988). Changing intentions. The antecedents of behavioral intentions are, according to the theory of reasoned action, the persons attitude toward the behavior and his or her infixed norm.The attitude toward the behavior refers to the evaluation of the behavior as desirable or undesirable, and the subjective norm is the perceived social pressure to perform or not to perform the behavior in question. The theory of planned behavior again adds to this model a consideration of volitional control. When issues of control arise, intentions are influenced not only by attitudes and subjective norms but also by perceived behavioral control (Ajzen and Madden, 1986 Schifter and Ajzen, 1985).A persuasive communication designed to influence intentions (and thus also behavior) can be directed at one or more of the intentions three determinants attitudes, subjective norms, and perceived behavioral control. Changing attitudes. We contract at the level of primary beliefs as we consider the determinants of a persons attitudes. According to the theory of reasoned action, attitudes are a employment of salient beliefs about the attitude object (a person, group, institution, behavior or other event). Each salient belief links the object to an attribute or to an outcome in the case of a behavior.The attitude is determined by the strength of these beliefs and by the evaluations associated with the attributes (Fishbein, 1963 Ajzen and Fishbein, 1980). Beliefs about the attitude object that are salient prior to presentation of the message can be elicited in a free-response format. The message is then constructed such that it will either change some of the existent beliefs, either in their strength or their evaluations, or introduce new beliefs into the belief system. Changing beliefs. To change a specific belief on an issue, the persuasive communication has to address some of the information on which the belief is based.Several probabilistic models that link prior information to a given belief have been proposed and validated (McGuire, 1960b Wyer and Goldberg, 1970 for a review see Slovic, Fischhoff, and Lichtenstein, 1977). These models suggest that the information introduced by the persuasive communication must be information from which the belief in question can be probabilistically inferred. Conclusions The focus in recent years on the central route to persuasion holds great promise for a better understanding of persuasive communication.This route deals with the nerve centre of the persuasion process, with changes in the fundamental beliefs on which the receivers attitudes and actions are based. Although much the Great Compromiser to be done, social psychologists have gained considerable insight into some of the cognitive processes that are at work during and Persuasive Communication Theory Page 13 after exposure to a persua sive communication, and into the practical aspects of constructing an effective message. SUMMARY This chapter provided a brief historical perspective on persuasive communication theory in social psychology.No attempt was made to discuss all theoretical developments in detail as this task would require a book in itself. Instead, the focus was on a few dominant lines of theoretical development, from the beginnings of scientific research on persuasion in the 1940s to the present day. The work initiated by Hovland and his associates tended to view the receivers of a persuasive communication as passively learning the information presented and then changing their beliefs and attitudes accordingly. This view led to a concern with contextual factors, and virtual dribble of the contents of the communication and its processing by the receiver.Few generalizable conclusions emerged from the research guided by this approach, and by the late 1960s the failure of the Hovland approach was widely a cknowledged. construct was recorded when attention turned from contextual or peripheral factors to persuasion via the central route. Contextual factors were found to be important only under conditions of low involvement or low ability to process the message. It was discovered, however, as a general rule, that receivers of a message are far from passive, prosecute in an active process of analyzing and elaborating on the information presented.It became clear that the effects of a persuasive communication could not be understood unless careful attention was given to these cognitive processes. Theoretical and empirical developments of the past two decades have enabled us to consider receivers cognitive responses during exposure to a message, yielding to the arguments contained in the message, and the messages impact on other beliefs not explicitly mentioned. These developments have also resulted in a much closer examination of the contents of persuasive communications, with an eye tow ard selecting arguments that will have the maximum effect on the target of the influence attempt.In this way, the theoretical developments of recent years have important implications for the practitioner who is concerned with constructing effective persuasive communications. Persuasive Communication Theory Page 14 REFERENCES Ajzen, I. 1985. From intentions to actions A theory of planned behavior. In J. Kuhl &038 J. Beckmann, eds. Action-control From cognition to behavior. Heidelberg Springer 11-39. Ajzen, I. 1988. Attitudes, personality, and behavior. Chicago Dorsey Press. Ajzen, I. , &038 Fishbein, M. 1980. Understanding attitudes and predicting social behavior. Englewood-Cliffs, NJ Prentice-Hall. Ajzen, I. &038 Madden, T. J. 1986. Prediction of purposive behavior Attitudes, intentions, and perceived behavioral control. 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