I am working on my thesis project and have come across a problem with the statistics which I am looking for a bit of guidance.
I am running ANOVA tests to determine significance between groups but i have come across a problem with a couple of the results which do not have equal variance (p<0.05 & p<0.001). This alone wasn't particularly a problem (Welch correction and unequal variance post-tests)
But one of my assays shows non-normal distribution & unequal variance:
- I ran D’Agostino-Pearson omnibus test with P<0.05 in one of the groups (however my sample sizes are small 3 datasets with n=7,15,&16).
- In the literature it appears there is some skew in this distribution from the 'healthy' adult population so it is reasonable to assume it is not normal in my groups.
- Bartletts test for homogeneity of variance has p>0.01.
It was recommended I run Kruskal-Wallis ANOVA, but: - This test assumes equal variance, which is not the case. - Also my sample size is a bit small in the first patient group (n=7), which to my understanding is that Kruskal-Wallis has little power in this case as well?
I essentially do not know what to do with this data set! Any help would me most appreciated!