I know ANOVA with percentages as already been discussed (Using ANOVA on percentages?) and (ANOVA-like test for bounded variables (percentages)), but the variables seemed different from my case.
I have to define the appropriate statistical analysis for an experiment to be carried out.
We have 7 groups with equal size (n=4). The factor is a nominal variable.
The measured variables are concentrations in specific areas of the sample and their corresponding percentages, calculated as "concentration in area" / "total concentration".
I read percentages may not meet the normality assumptions of ANOVA, especially in the case of extreme values (close to 0% or 100%).
My idea was to:
- use ANOVA if the percentages are in the range 20%-80% (recommended elsewhere)
- use Kruskal-Wallis if extreme values are present.
Would someone agree on this solution?