Rasch models are characterised by sufficient statistics for all parameters. In the Rasch unidimensional model for two ordered categories, the parameterisation of the person and item is symmetrical and it is readily established that the total scores of a person and item are sufficient statistics for their respective parameters. In contrast, in the…

This book discusses adapting pencil-and-paper tests to computerized testing. Mention is made of models for graded responses to items and of possibilities beyond pencil-and-paper-tests, but the book is essentially about dichotomously scored test items. Contrasts between item response theory and classical test theory are described. (SLD)

Applying the principles of latent trait analysis makes it possible to rank order profiles of students seeking college admission in terms of the adequacy of a single score. An illustration using 577 profiles shows that it is possible that only a subset of profiles may require qualitative analysis. (SLD)

This paper describes the use of the Rasch model to help implement computerized administration of the standard and advanced forms of Raven's Progressive Matrices (RPM), to compare relative item difficulties, and to convert scores between the standard and advanced forms. The sample consisted of 95 girls and 95 boys in Australia. (SLD)