Published On: 26/01/2012|Categories: 2008–2012, Vol.33 (1), Vol.33 (2012)|


Model-based attempts to rigorously study the broad and imprecise concept of ‘discriminating power’ are scarce, and generally limited to nonlinear models for binary responses. This paper proposes a comprehensive framework for assessing the discriminating power of item and test scores which are analyzed or obtained using Spearman’s factor-analytic model. The proposed framework is organized on the basis of three criteria: (a) type of score, (b) range of discrimination, and (c) conceptualization and aspect that are measured. Within this framework, the functioning and interpretation of 16 measures, of which 6 appear to be new, are discussed, and the relations between them are established. The usefulness of the proposal in psychometric FA applications is illustrated by means of an empirical example.

Open Access