This question is about SAS/STAT and I think this forum might be the best fit for my question.
In categorical data analysis, SAS generates Somers' D to test the association strength between categorical variables.
In SAS, both Proc Freq and Proc Logistic generate Somers' D. My question is what is the difference between the Somers' D from Proc Freq and Proc Logistic?
Most of time, Somers' D from Proc Logistic (when only one factor is applied) is quite closed to the Somers' D from Proc Freq. However, they could also be quite different. Could someone tell me what make values from both Procedures so different?
The method of calculation may differ quite markedly for each procedure to allow for the functionality provided by the analysis.
The calculation method for each procedure is explored in great detail, and will make profound sense to someone who understands statistical techniques and the limitations of particular interpretive methods.
If you don't have SAS/Help installed, look up the product documentation on the SAS website, navigate through the product and look at the background material supplied for the appropriate procedure.