By entering frequencies into a 2 x 2 table, you can calculate various statistics to evaluate the relationship between two dichotomous variables. Thus, the 2 x 2 option can be used as an alternative to correlation when the two variables of interest are dichotomous. STATISTICA will also compute the McNemar Chi-square test for the significance of changes. In that case, you can think of the 2 x 2 option as an alternative to the t-test for dependent samples when the variable of interest is dichotomous. See 2x2 Tables - Quick tab for further details.