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Can you generate a letters report after conducting the Steel-Dwass nonparameteric comparison?

zachary_scott0

Community Trekker

Joined:

Mar 31, 2016

If you run a similar test like Tukey's JMP generates a "connecting letters report." However our data is non-normal and the variances are heterogeneous so we needed to use the Kruskal-Wallis test to examine variance and then used Steel-Dwass to compare means for all pairs of treatments. How can we get a similar letters report after doing this analysis?

Thanks,

Zach

3 REPLIES
dknayyar080

Community Member

Joined:

Jul 4, 2016

Were you able to get find a way to do this? I am currently need to do some steel dwass as well but have no idea how to get the connecting letters. Any help would be great. Thank you!

tpinck27

Community Trekker

Joined:

Jan 13, 2016

I've also been looking for a way to do this, I'm sure you could script it somehow but don't have the necessary scripting ability.

zachary_scott0

Community Trekker

Joined:

Mar 31, 2016

It appears there is no way built-in to the program, and I am not savvy with coding (hence using JMP instead of SAS). I imagine SAS has more options for this but I switched to JMP because of the ease of use. Depending on your data it may be fine to simply run an ANOVA and use Tukey's or similar if you can correct the variance with a tranformation or rely on the Welch ANOVA if not.

Turns out the assumption of normality does not always have to be met:

Experiments in Ecology, by A.J. Underwood. 2006. Cambridge University Press (pages 192-193)