A FACTOR ANALYSIS OF PSYCHOTIC BEHAVIOR
Available instruments designed to facilitate the differential diagnosis of severe handicaps were developed almost exclusively through qualitative methods. Inconsistencies in the scales thus developed have failed to resolve the confusion surrounding differential diagnosis. In an effort to illustrate how one quantitative method (i.e., factor analysis) can assist in the resolution of the problem, the authors describe the construction of the Psychotic Behavior Rating Scale (PBRS) and compare the factor analytically derived scale with five existing instruments. Similarities and dissimilarities among the various scales are noted.