Complex & Within Ss Designs

Turn in a paper copy of your work.

A.

Sixteen subjects participated in this study. At the start of the experiment, subjects were randomly assigned to one of two, equally-sized groups: subjects in one group were put into a positive mood and subjects in the other group were put into a negative mood. Subjects then were given a list of 20 words to memorize. One week later, the subjects returned to the laboratory for the recall session. Again, subjects were randomly assigned to one of two, equally-sized groups: subjects in one group were put into a positive mood and subjects in the other group were put into a negative mood Subjects then were asked to recall the words they had learned the previous week. The dependent variable is number of words recalled.

1. Draw 2 X 2 grid representing this study.
2. State dependent memory argues that we will have better recall if our mood at learning matches our mood at recall. Based on this theory:
   • Do you predict a main effect for mood at learning? If so, what is it?
   • Do you predict a main effect for mood at recall? If so, what is it?
   • Do you predict an interaction? If so, what group(s) will recall the most words?
3. Draw a line graph depicting your interaction hypothesis. What sort of interaction is it -- spreading or cross-over?
4. Test your predictions by entering the data below into SPSS and running a 2 X 2 ANOVA. (“Analyze” > “General Linear Model” > “Univariate”). Request the marginal means (rather than “descriptive statistics”) for the main effects and interaction, and also request an effect size estimate.  Use eta-squared for the interaction effect (if significant).
5. Type a paragraph reporting the results of your ANOVA. Present the appropriate statistical information for first the two main effects, and then the interaction (include means for statistically significant effects).

Data

B.

In social psychology, there are two competing theories about self-esteem. One theory posits that people who have low self-esteem prefer negative feedback about themselves. The theory is called self-verification. The reasoning is that a person prefers to maintain a consistent self-view rather than be confused by contradictory information that may prove to be false later. So, people with low self-esteem would prefer negative feedback over positive feedback because it would prevent them from having to change their self-view and from potentially realizing later that that positive feedback was wrong after all.  A competing theory is called self-enhancement. This theory posits that everyone wants to look and feel as good as possible no matter what. So, this theory would predict that people who have low self-esteem would like positive feedback just as much as people with high self-esteem.

Below is the FAKE data from a FAKE study testing these hypotheses.

Ten high self-esteem participants and 10 low self-esteem participants were randomly assigned to receive either negative or positive feedback from a confederate: "You don't seem to be very good at this task; it seems like the kind of thing you're just not cut out for” versus "You did a really great job on this task; you really seem to have what it takes.” The dependent variable was participants' liking for the confederate measured on a 9-point scale (higher scores indicate greater liking). Thus, this was a 2 (self-esteem) by 2 (feedback) quasi-experimental factorial design.

1. What makes this design “quasi-experimental”? What makes it a 2 x 2? What makes it factorial?
2. Enter the raw data into SPSS and conduct a 2 X 2 ANOVA.
3. Write a paragraph reporting the results of this analysis including effect size information.
• What aspects of the statistical results indicate the data is probably fake?
4. What do the results tell you about self-verification versus self-enhancement theory? Looking back at the design of the study, can you think of a reason why we could not call this experiment a test of the theory that people like feedback that matches their self-esteem?
5. If you had failed to include self-esteem as a factor in this study, and you had simply run a t-test to see if people preferred positive or negative feedback, what would you have found?
   • Check your prediction by actually conducting that analysis, and report the results. In what way are those t-test results misleading?

Data

C.

Researchers gave White college students two resumes in an experiment in which they were asked to play the role of an employment officer. It was a within-subjects design. The resumes were designed to have equal qualifications, but one had a photo of an African-American applicant attached, and the other had a photo of a White applicant. The researcher found that there were no significant differences between the evaluations of the Black applicant and the White applicant. The researcher concludes that the student's judgments were not influenced by the race of the applicant. Why might you question that conclusion?