As well as using Roy's GCR (for between-within contrasts), Psy also makes use of the studentized maximum root distribution when getting the critical constant for the simultaneous testing procedure, when you have data from a balanced 2 factor fixed-effects design.
Need to read about, and work out how to implement, the SMR distribution.
See Bird & Hadzi-Pavlovic (2005). Studentized maximum root procedures for coherent analyses of two-factor fixed-effects designs and Boik (1993). The Analysis of Two-Factor Interactions in Fixed Effects Models.
As well as using Roy's GCR (for between-within contrasts), Psy also makes use of the studentized maximum root distribution when getting the critical constant for the simultaneous testing procedure, when you have data from a balanced 2 factor fixed-effects design.
Need to read about, and work out how to implement, the SMR distribution. See Bird & Hadzi-Pavlovic (2005). Studentized maximum root procedures for coherent analyses of two-factor fixed-effects designs and Boik (1993). The Analysis of Two-Factor Interactions in Fixed Effects Models.