Study examined the factorial invariance of responses by preadolescent males and females to a multidimensional self-concept instrument. Also demonstrated how confirmatory factor analysis is used to test factorial invariance and examined problems with its use and interpretation. (RB)

Classical methods for detecting outliers deal with continuous variables. These methods are not readily applicable to categorical data, such as incorrect/correct scores (0/1) and ordered rating scale scores (e.g., 0,..., 4) typical of multi-item tests and questionnaires. This study proposes two definitions of outlier scores suited for categorical…