Standard approaches for estimating item response theory (IRT) model parameters generally work under the assumption that the latent trait being measured by a set of items follows the normal distribution. Estimation of IRT parameters in the presence of nonnormal latent traits has been shown to generate biased person and item parameter estimates. A…

The use of mean inter-item correlation as a technique for examining homogeneity is proposed as a descriptive tool that can orient researchers to salient aspects of their scales. A study of 341 undergraduates who completed the NEO Personality Inventory illustrates the technique. (SLD)