This book uses concepts familiar to those with a working knowledge of basic statistics and classical test theory to present item response theory models that are currently in wide use in both practical testing and research. The book would serve as a good entry-level graduate text in psychometrics and measurement methods. (SLD)

Reliability and validity of 4-point and 6-point scales were assessed using a new model-based approach to fit empirical data from 165 graduate students completing an attitude measure. Results suggest that the issue of four- versus six-point scales may depend on the empirical setting. (SLD)