 a scientific theory is a set of related assumptions that allows scientists to use logical deductive reasoning to formulate testable hypotheses .

 a set of related assumptions
 a set of related assumptions
 a set of related assumptions
 logical deductive reasoning
 testable

 cognitive dissonance theory
 cognitive dissonance: uncomfortable feeling or stress caused by holding two contradictory ideas simultaneously.
 "dissonant" vs. "consonant"
 the theory of cognitive dissonance proposes that people have a fundamental cognitive drive to reduce this dissonance by modifying an existing belief, or rejecting one of the contradictory ideas.

 1)the introduction of a new cognition that is dissonant with a currently held cognition creates a state of "dissonance"
 2) the magnitude of the “dissonance” relates to the relative importance of the involved cognitions
 3) dissonance can be reduced either by eliminating dissonant cognitions, or by adding new consonant cognitions.
 4) the maximum possible dissonance is equal to the resistance to change of the less "resistant cognition"; therefore, once dissonance reaches a certain level, one of the dissonant cognition will be changed or eliminated, and dissonance will be reduced.
 Q: Are they relevant? Are they directly testable?

 human beings, when persuaded to lie without being given sufficient justification, will carry out the task by convincing themselves of the falsehood, rather than telling a bald lie
 Q: Does it flow from the previous assumptions?
Is it testable?

 Festinger’s experiment
 students were made to perform tedious and meaningless tasks
 participants rated these tasks very negatively.
 after a long period of doing this, students were told the experiment was over and they could leave.

 however, the experimenter then asked the subject for a small favor.
 the participant was asked to fill in as a research assistant and try to persuade another subject that the dull, boring tasks the subject had just completed were actually interesting and engaging.
 some participants were paid $20 for the favor, another group was paid $1, and a control group was not requested to perform the favor.

 when asked to rate the peg-turning tasks later, those in the $1 group rated them more positively than those in the $20 group and control group.
 Q: Is this explainable by the cognitive dissonance theory? How is the result related to the theory?

 other ways of forming the hypotheses
 people who feel dissonance will seek information that will reduce dissonance and avoid information that will increase dissonance
 people who are involuntarily exposed to information that increases dissonance are likely to discount that information, either by ignoring it, misinterpreting it, or denying it.

 alternate theories exist because the very nature of a theory allows the theorist to make speculations from a particular point of view.
 observations are colored by the individual observer’s frame of reference, so there may be many diverse theories.

 generates research : generates a number of hypotheses that can be investigated through research.
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 descriptive research hypothesis testing
 organizes data into a meaningful structure, provides an explanation for the results, and help ask further questions.
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Integrate knowledge into an intelligible framework shape as many bits of information as possible into arrangement

 falsifiable : can be confirmed or disconfirmed
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 be precise enough negative research results: refute the theory; suggest discard or modify it
 guides action : provide the practitioner with a guide to action
 internally consistent
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 components logically compatible consistent use of language
 parsimonious : be as simple as possible

 determinism vs. free choice
 pessimism vs. optimism
 causality vs. teleology
 conscious vs. unconscious determinants of behavior
 biological vs. social influences on personality
 uniqueness vs. similarities

 personality inventories
 reliability : does it yield consistent result?
 validity : does it measure what it intends to measure?
• Construct validity : the extent to which an instrument measures some hypothetical construct such as intelligence, extraversion, etc.
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Convergent validity
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Divergent validity
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Discriminant validity
• Predictive validity : the extent that a test predicts future.