Aug
17
I Will Not Ever, NEVER Run a MANOVA
I have been thinking to write a paper about MANOVA (and in particular why it should be avoided) for some time, but never got round to it. However, I recently discovered an excellent article by Francis Huang that pretty much sums up most of what I'd cover. In this blog post I'll just run through the main issues and refer you to Francis' paper for a more in-depth critique or the section on MANOVA in Serious Stats (Baguley, 2012).
I have three main issues with MANOVA:
1) It doesn't do what people think it does
2) It doesn't offer Type I error protection for subsequent univariate tests (even though many text books say it does)
3) There are generally better approaches available if you really are interested in multivariate research questions
Let's start with the first point.
I have three main issues with MANOVA:
1) It doesn't do what people think it does
2) It doesn't offer Type I error protection for subsequent univariate tests (even though many text books say it does)
3) There are generally better approaches available if you really are interested in multivariate research questions
Let's start with the first point.
