3
Experimental Research Methods (Fach) / L10 (Lektion)
After this lecture and studying the materials, students are able to:
• Explain how a one-way ANOVA is different from a repeated measures ANOVA
• Interpret the SPSS output of a repeated measures ANOVA with a within-subjects factor
• Interpret the SPSS output of a repeated measures ANOVA with a within-subjects factor and betweensubjects factor
Diese Lektion wurde von tklmn erstellt.
Diese Lektion ist leider nicht zum lernen freigegeben.
- SSs : Differences between scores in one column are not just attributed to error, but also to subjects →effect of subject
- SSsxtime: Effect of cell SiYk that cannot be attributed to effect Si or to effect Yk• SSSxtime acts as error or within in test of the effect of time: ‘SSW’ = SSSxtime• Differences between scores in one column after taking the effect of the factor Subject into accountis attributed to error → this is SSSxtime
- Repeated Measures ANOVA: Assumptions • Assumptions of repeated measures ANOVA are comparable to those of ANOVA1. Independence of errors/interaction effects → observations at each time point/within eachtreatment condition must be independent2. Population distribution within each treatment must be normal → residuals normally distributed3. Error covariance matrix meets sphericity assumption• “The variance of the difference score between two levels of the within-subject factor must be thesame for any pair of levels”• That is, take two treatment levels and subtract the scores for one level from scores of anotherlevel, the resulting difference score must have the same variance for every pair of levels