If the response has two levels, you can use this option to compare response proportions for the X levels to the overall response proportion. This method uses the normal approximation to the binomial. Therefore, if the sample sizes are too small, a warning appears in the results.
Note: For a description of Analysis of Means methods, see the document by Nelson, Wludyka, and Copeland (2005). For a description of the specific Analysis of Means for Variances method, see the paper by Wludyka and Nelson (1997).