Chi square post hoc tests and correction for multiple testing

[Andrzej_Andrew]

Hi,
I did not find a possibility to check Bonferroni or Holm correction
for multiple comparisons ? How does it work here in Jamovi and how to spot the differences between groups
in output chi squre test result windows, in other words, how to find what is compared with what and where do
statistical differences occur ?

kind regards and thank you,
Andrzej

[MAgojam]

Hey @Andrzej_Andrew,
Thanks for your question about Bonferroni or Holm corrections for multiple comparisons in jamovi's chi-square test.

In jamovi, after a significant chi-square test, the standard and most informative way to understand where the statistical differences lie within your contingency table is by examining the Standardized Residuals and Deviance Residuals (both found under the "Cells" options in the output).
Here's why these are sufficient and why traditional multiple comparison corrections like Bonferroni or Holm are generally not applied in this specific context:

• What they tell you: These residuals indicate how much the observed count in each cell deviates from what would be expected if there were no association between the variables.
  Standardized Residuals are a form of adjusted Pearson residuals, which are approximately normally distributed, allowing you to identify cells with significant deviations (e.g., an absolute value greater than ~1.96 for a 5% significance level).
  Deviance Residuals, calculated from a Poisson Generalised Linear Model (GLM) as implemented in the module, are particularly robust for assessing cell-wise contributions to the chi-square's significance.

• Why corrections aren't needed: Unlike post-hoc tests for ANOVA (which compare multiple pairs of means and thus require correction to control the Type I error rate), the analysis of residuals in a chi-square test is a diagnostic tool for the overall table. You are not performing multiple independent pairwise comparisons between groups in the same way. Instead, you are assessing each cell's contribution to the observed deviation from independence.

In essence, the standardized and robust deviance residuals directly answer your question about "where statistical differences occur" by pinpointing the specific cells driving the chi-square's significance.

Kind regards,
Maurizio
https://www.jamovi.org/about.html

[Andrzej_Andrew]

Thank you very much indeed Maurizio for your kind help.
Just to clarify things a little bit.
I have watched this:
https://www.youtube.com/watch?v=GnThiGZ-g5U
and the tutor is using adjusted residuals and simple Bonferroni correction.
This is why I asked my question. So is it OK to do it in a way like in YT video as well ?
I would be grateful for your kind comment.

kind regards,
Andrzej