ABSTRACT
As you read scientific reports describing clinical assessment instruments, you are likely to encounter many studies that describe factor analyses of assessment mea sures. The term factor analysis refers to a set of statistical techniques that, although mathematically complex, have the conceptually straightforward property of identifying a small number of underlying dimensions within a large number of data points. This set of techniques is used frequently in clinical assessment research. Clinicians often mea sure numerous behaviors, events, markers of personality traits, attitudes, or aspects of intellectual functioning. Frequently, researchers are interested in either exploring whether those numerous indicators can be summarized in terms of a smaller number of underlying dimensions or testing hypotheses about underlying dimensions of the mea sured phenomena.
