Dear All: I'm running a repeated measures of ANOVA using stat>>general linear model>>repeated measures from SPSS v.10. I have one within-subject effect (before and after workshop) and four between-subject effects (sex, discipline, learning_style, and status). I have 24 subjects. First run: When I specify the model with only all main and all two-way interaction effects initially, I have significant effects for within-subjects (workshop, workshop*status, workshop*learning_style*gender) and for between-subjects (learning_style, learning_style*gender, gender*discipline and status*discipline). Second run: Next I re-ran the model with the significant main and two-way interaction effects identified in the first run. That is, the within-subject effects is before and after workshop. The between-subject effects are learning_style, status, gender, discipline, learning_style*gender, gender*discipline, status*discipline. What I found is that some main and interactions are not significant anymore and also some main effects are significant which was insignificant in the first run. I also found that depending on which main and interactions are specified in the model, the significant main and interaction effects changes.
My question is why different results? Do I need to report the results from the first run or second run? I appreciate any comments. Thanks. Sangdon Lee, Ph.D., . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
