PQStat PQStat User Guide Polski pqstat.pl

Test selection diagram – more than two groups

Interval scale Ordinal scale Nominal scale Y N Y Y Y N N N Y N Y N normality tests Levene,Brown-Forsythe test Mauchly test Are the datanormallydistributed? Are the datadependent? Are thevariancesequal? ANOVA forindependent groups Is sphericitymet? ANOVA fordependent groups MANOVA or ANOVAwith correctionEpsilon, GG, H-F ANOVA forindependent groupswith correction F* and F″ Are the datadependent? Friedman ANOVA Kruskal-WallisANOVA Are the datadependent? Q-Cochran ANOVA multidimensionalχ² test

Note
The proposed test selection scheme for the multiple group comparison is not the only possible scheme and does not include all the tests proposed in the software for this comparison.
Note
Note, that simultaneous comparison of more than two groups can NOT be replaced with multiple performance the tests for the comparison of two groups. It is the result of the necessity of controlling the I type error \(\alpha\). Choosing the \(\alpha\) and using the \(k\)-fold selected test for the comparison of 2 groups, we could make the assumed level much higher \(\alpha\). It is possible to avoid this error using the ANOVA test (Analysis of Variance) and contrasts or the POST-HOC tests dedicated to them.