Assessing Acquiescence in Binary Responses: IRT-Related Item-Factor-Analytic Procedures

This article proposes procedures for assessing acquiescence in a balanced set of binary personality items. These procedures are based on the bidimensional item-factor analysis model, which is an alternative parameterization of the bidimensional 2-parameter normal-ogive item response theory model. First the rationale and general approach are described. Then methods for specifying and fitting the model and for estimating the individual factor scores, are discussed, as well as several validity criteria for supporting the suitability of the proposed solution. Finally, we illustrate the procedures using empirical data and discuss their usefulness for applied personality measurement.