ANOVA-pos hoc

Posted by OliverDZ on Jun 29, 2013; 11:18am
URL: http://spssx-discussion.165.s1.nabble.com/ANOVA-pos-hoc-tp5720943.html

Safe my life!!
my study includes  4 groups, 20 subjects each. ANOVA with Tukey/Bonferroni test shows seemingly contradictory results;
1. Though A and B (controlling groups) are equal (not significant), C-A is equal (insignificant), but C-B is not equal (significant).
2. I used Games-Howel post hoc since Levene's Test indicating unequal variance (less that 0.05), it really reduces the occurrence of such results, but still encountering few cases.