Need for bonferroni correction I need help understanding if I need to / how to apply a bonferroni correction!
I have one continuous variable and three unrelated groups that have completed scores on this variable (Groups: A,B,C). I planned to conduct 4 pairwise comparisons with this outcome variable (A-B, A-C, AB-C and A-BC).
Unfortunately normality is violated so I plan to conduct non-parametric Mann Whitney U tests for these comparisons.
Do I need to apply a bonferroni correction here (.05*4?) or as I am only looking at one outcome variable does this not apply?
Are there alternative methods that may be more suitable?

Using bonferroni correction on multiple comparisons is correct, but there are some points to consider:

*

*If your research is explorative or/and you don't have an adequate
sample size I would avoid bonferroni correction (you already
have a low power and it is really difficult you will achieve some
results);


*If the comparisons are not the main endpoint of your research I would avoid bonferroni correction;


*If you will perform a lot of multiple comparisons i would use it, otherwise if you will preform few tests the correction makes little difference;


*How you will interpret the results: If the rejections of a single test will be considered a success the bonferroni correction could be a good idea otherwise if you consider a success the rejections of more than one test you could avoid it (considering the number of comparisons);
There are certainly a lot of things to consider before deciding to apply the bonferroni correction, take always in mind that it is a conservative method.
