Psy 521/621
Lab Assignment #9
Due: December 3, 2008 in Lab
Repeated-Measures ANOVA
Finding an Example of the ANOVA for Dependent Groups (Repeated Measures)
1. Your task is to find an empirical journal article that uses a oneway ANOVA for dependent groups (repeated measures) or a mixed factorial ANOVA. In no more than one page, you are to summarize the article in general, discuss specifically what was concluded based on the ANOVA along with any post-hoc tests conducted (if more than one is presented choose the most interesting one and discuss the conclusion reached from that one test), and offer a brief critique of the paper. Be sure to include a copy of the article with your assignment.
Data Exercises
2. A social psychologist was interested in the effects of time on attitude change. Eight adults were approached at public locations to participate in the study at which point initial attitude was assessed (on a scale from 1 – 10, 10 being most favorable) towards a political issue that most people don’t care about (election of a local fire marshals). After this initial assessment, participants were asked to read a pamphlet on this issue and attitude towards the issue was assessed a second time. Research assistants contacted these participants once a week for the next three weeks, each time assessing attitude towards the issue. The data appear below. How does attitude change as a function of the brochure and over time? Analyze this data using the repeated-measures ANOVA. Conduct post-hoc tests as necessary. Write up the results of your analyses in APA format including a figure to illustrate the patterns in the data.
Initial / Post-brochure / Week 2 / Week 3 / Week 43.00
2.00
3.00
5.00
1.00
1.00
2.00
2.00 / 4.00
5.00
3.00
6.00
5.00
3.00
4.00
3.00 / 4.00
5.00
3.00
5.00
5.00
5.00
4.00
4.00 / 3.00
4.00
3.00
2.00
3.00
4.00
4.00
4.00 / 3.00
4.00
2.00
2.00
2.00
4.00
2.00
2.00
3. Dana wished to evaluate the effects of conflict-resolution training on the social skills of elementary school children. Fourth-grade students in a school district were randomly assigned to one of two groups, one group receiving conflict-resolution using a cognitive-based approach and the other group receiving a behavior-based approach. To measure the effects of the treatment, ratings of the children’s social skills were completed by teachers and by the parents of these students. Higher scores on these rating imply better social skills. The data for this study appear in social.sav. Analyze this data using a mixed-factorial ANOVA. Conduct post-hoc tests as necessary. Write up the results of your analyses in APA format including a figure to illustrate the patterns in the data.