How does SPSS compute the Bonferroni adjusted alpha used in their >2x2 Chi-square tests?

Posted by Emet Schneiderman on Oct 13, 2016; 2:39pm
URL: http://spssx-discussion.165.s1.nabble.com/How-does-SPSS-compute-the-Bonferroni-adjusted-alpha-used-in-their-2x2-Chi-square-tests-tp5733251.html

My question concerns how SPSS v22 does Bonferroni corrections for chi-square tests on contingency tables > 2x2 (nominal data). For example when doing the post-hoc pair-wise comparisons between the 4 groups (in columns), are the adjustments based on just the row or the whole matrix? For the former, the adjusted alpha level (threshold) would be 0.0083, (.05/6); for the latter it would seem to be .00167 (.05/30). Which are they using to declare that a p-value is significant, while preserving the experiment-wise alpha of 0.05? Their documentation is unclear on this issue.