Hi
I have been asked to look at a students analysis, where the chosen test is kruskal wallis
He is looking at the difference between 3 groups, the maximum numbers he has in the 3 groups are :
5, 7 and 4
And for a second analysis
5, 6 and 6
For all of the remaining analyses he has one of the group with 2 cases
I have come across the following and would be interested in any comments on the sample size within each group. None of the results are significant, and I think this is the result of the small numbers.
" If you have small samples, the Kruskal-Wallis test has little power. In fact, if the total sample size is seven or less, the Kruskal-Wallis test will always give a P value greater than 0.05 no matter how the groups differ." (http://www.graphpad.com/articles/interpret/anova/kruskal_wallis.htm)
Any comments
Regards
Ann
Ann E Fitzmaurice
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