You Can't Classify All of the People All of the Time.

When performing a classification study, it is sometimes a sound strategy not to classify all subjects but to leave a residue of unclassified entities to be analyzed separately. Starting from an interactional paradigm, theoretical reasons for this approach were given. A procedure, RESIDAN, for carrying out a classification analysis using a residue was presented and empirical results for two data sets were given, both of which indicated that belonging to a residue is a property of individuals that has a significant stability over time. Although RESIDAN can be applied to data from a single measurement period, test-retest data are useful for separating subjects with true deviant patterns from subjects with deviant patterns caused by errors of measurement. It was argued that the concept of antitype (= rare pattern) has theoretical significance and could be studied within the presented framework.