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Unformatted text preview: 2-17-11Participant’s Perceptions as Extraneous Variables•Response BiasoYea-sayersParticipants who tend to answer yes to all questionsoNay-sayersParticipants who tend to answer no to all questions•Response setoThe experimental context or testing situation influences the participants’ responsesControlling Participants Effects•Demand CharacteristicsoDouble-blind experiment: both the experimenter and the participants are unaware of which treatment is being administered to which participants•Yea-saying: the most typical control for yea-saying (and nay-saying) is to rewrite some of the items so that a negative response represents agreement (control for yea-saying) or a positive response represents disagreement (control for nay-saying)•Response Set: the best safeguard against response set is to review all questions that are asked or items to be completed to see if a socially desired response is implied in any mannerChapter 8 – Internal and External ValidityInternal Validity: Evaluating Your Experiment from the Inside•Internal ValidityoWay to evaluate your experimentoWant to ensure that your IV is the only explanation for the DVoIf there is another explanation besides the IV for resulted DV what would it be called? How can we fix this problem? Confound, extraneous, alternate explanation/ Control techniquesInternal Validity: Child Abduction Example•Research has shown hat child abduction is a major problem in our society, the vast majority of young children are susceptible, and the abductions may be prevented by teaching children to resist enticements.•Goal: Teach children, upon being enticed by stranger, to say “No, I have to go ask my teacher” and then to quickly run away•The experimenter wanted to evaluate the effectiveness of a 20-min. interactive videotape program that was designed to teach children these behaviors in a school setting•She selected students in first grade classes at an elementary school, all whom...
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- Spring '11
- external validity, internal validity, generalization probe