Games-Howell Test (Tukey HSD with Welch's Correction for Unequal Variances) in Fit Y by X

[cwillden]

This is probably the most frequent limitation of JMP at my organization.  Unequal variances suggest to use Welch's ANOVA, but options are limited for multiple comparisons with unequal variances.  Steel-Dwass doesn't work well with small sample sizes and it's not clear that it is robust to very unequal variances.

Games-Howell test is effectively a Welch's version of Tukey's HSD and works well with small sample sizes.

[bpmaruszewski]

Has a solution for this issue been determined? I too am looking for the Games-Howell post hoc test or something comparable for multiple comparisons when unequal variances and small samples sizes are present.

[cwillden]

No movement on this yet from what I can tell, but I started creating an add-in for it recently.  Right now, I have it functioning for X and Y inputs, but hope to incorporate a By variable when I get a chance.  You can try it now if it would be helpful for you.  Here's a snippet of the dialog and report.  Feel free to PM me and I will send it to you.  Recall and Help buttons are also non-functional right now.GH Dialog.png

GH_output.PNG

[cwillden]

**Update:  I uploaded an add-in version of my application to the File Exchange: Games-Howell Test (Tukey HSD with Welch's correction for Unequal Variances) 

[Sarah-Sylvestre]

Hi @cwillden , thank you for your suggestion! We have captured your request and will take it under consideration.