Binary outcomes that depend on an ordinal predictor in a nonmonotonic way are common in medical data analysis. Such patterns can be addressed in terms of cutpoints: for example, one looks for two cutpoints that define an interval in the range of the ordinal predictor for which the probability of...

This note is a comment on the article "Dimension Reduction for Classification with Gene Expression Microarray Data" that appeared in Statistical Applications in Genetics and Molecular Biology (Dai et al., 2006).