John Uebersax's resource for researchers interested in latent class analysis and latent class models.

Bounded optimisation code (FORTRAN) for numerical analysis, from Northwestern University.

This website by Lawrence Rudner introduces Item Response Theory, and includes a complete on-line book.

Offers clinical assessment courses, counseling, training and the Wartegg testing methodology.

Offers online practice psychometric tests and courses developed by experienced psychologists.

Rasch Scaling information from MESA at the University of Chicago. Includes full text articles.

Free downloadable software for analysing repertory grids.

Introduction to factor analysis, with worked examples.

Describes the Bayesian approach to factor analysis, which incorporates prior information and eliminates the need for rotation. Includes some full-text articles.

Provides information, resources, and sample ability tests and personality questionnaires. Includes tips on taking tests and how to prepare for them.