Feature request: Kendall's W effect size for Friedman ANOVA

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m_reutter
Posts: 1
Joined: Fri Jun 12, 2026 10:15 am

Feature request: Kendall's W effect size for Friedman ANOVA

Post by m_reutter »

Dear jamovi team,

I'm an enthusiastic R user and I always tell my bachelor's and master's students to use jamovi instead of SPSS. I really love your work and hope you will get more and more users!
I have a small feature request: While we have partial eta squared for (parametric) ANOVA and epsilon squared for Kruskal-Wallis ANOVA, there is currently no measure of effect size available in the Friedman ANOVA.
There is an easy implementation to calculate Kendall's W from the x² test statistic:

Code: Select all

W = x² / (N*(k-1))
where N is the number of independent observations and k is the number of levels of the repeated measures factor
Reference: https://search.r-project.org/CRAN/refma ... fsize.html

I would love to see Kendall's W implemented in a future version of jamovi!

Thank you for your great work and kind regards,
Mario Reutter-Dieker
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jonathon
Posts: 2988
Joined: Fri Jan 27, 2017 10:04 am

Re: Feature request: Kendall's W effect size for Friedman ANOVA

Post by jonathon »

ask not what jamovi can do for you! but what you can do for jamovi! :P

Feel free to open a PR over here:

https://github.com/jamovi/jmv

cheers

Jonathon
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