| Paul Barrett: Free software for (advanced) psychometric analyses. Also a number of presentations on psychometrics. |
| Applied Psychometric Society: Resource for professionals in psychometrics. Operated by Fordham University. |
| Article: Increasing the Validity of Adapted Tests: Hambleton & Patsula (1999) article providing guidelines for adapting tests for cross-cultural and international uses--includes the ITC's Test Adaptation Guidelines |
| Bayesian Factor Analysis: Describes the Bayesian approach to factor analysis, which incorporates prior information and eliminates the need for rotation. Includes some full-text articles. |
| Factor Analysis: Introduction to factor analysis, with worked examples. |
| Ingrid Yahoo Group: Free downloadable software for analysing repertory grids. |
| Institute for Objective Measurement: Rasch Scaling information from MESA at the University of Chicago. Includes full text articles. |
| Item Response Theory: This website by Lawrence Rudner introduces Item Response Theory, and includes a complete on-line book. |
| L-BFGS-B Nonlinear Optimization Code: Bounded optimisation code (FORTRAN) for numerical analysis, from Northwestern University. |
| Latent Class Analysis and Latent Class Models: John Uebersax's resource for researchers interested in Latent Class Analysis (LCA) and Latent Class Models. Includes factor analysis of binary data. |
| Latent Variable Interactions and Quadratics: Resources focused on latent variable interactions and quadratics. Includes a bibliography, FAQ, Excel templates, full text articles, and full text monograph. |
| Maydeu-Olivares, Albert: Albert Maydeu-Olivares' homepage at the University of Barcelona: includes some unpublished working papers. |
| Multidimensional Scaling: Searchable bibliography and selection of recent papers, from the University of Newcastle. |
| Multivariate Data Analysis: Outline for Michael Friendly's course on multivariate data analysis and linear statistical models in behavioural science research. Includes bibliographies, computing guides, notes, and SAS examples covering topics such as regression, ANOVA, and factor analysis. |
| Mx: Matrix algebra interpreter and numerical optimizer for structural equation modeling and other types of statistical modeling of data. Includes documentation and example code. |
| Personal Construct Psychology Research Group: University of Wollongong based research group. Resources include free software for analysing repertory grids, and searchable citation database of PCP references. |
| PMetric Psychometric Software System: Shareware for designing, applying, developing, and evaulating psychometric scales. The software features a scale editor, reliability analysis, central results database and other features. |
| Principal Components and Factor Analysis: Chapter from StatSoft's Electronic Statistics Textbook. |
| Promoting Stakeholder Acceptance of Computer-Based Testing: Jones (2000) article on communicating the value of and addressing issues regarding the implementation of computer-based testing. |
| Psychometric Software: Mountain Shadows Phonemic Awareness Scale (MS-PAS) and selection of Macintosh and Windows statistical analysis software, including parallel analysis. |
| Psychometrics Research Unit: Research results, questionnaires and publications of the Psychometrics Research Unit (University of Valencia, Spain). Content a mixture of English, Spanish, Valencian and Portuguese. |
| Psychometrika: Print journal of the Psychometric Society. Subscription and submission information and author instructions. |
| Reliability and Validity: Clear introduction to the nature and assessment of test reliability and validity. |
| RepGrid: Includes the Centre for Person-Computer Studies, Knowledge Support Systems, RepGrid and WebGrid software details, and the Personal Construct Psychology site. Many full-text articles for download. |
| Scientific Software International: Statistical software for the social sciences. Includes LISREL for structural equation modeling, HLM for hierarchical data analysis, and BILOG, BILOG-MG, MULTILOG, PARSCALE, and TESTFACT for IRT-based test analysis. |
| Structural Equation Modeling FAQ: Frequently asked questions for the SEMNET structural equation modeling discussion group. |
| The Correlation Coefficient: Online textbook by political scientist RJ Rummel. |
| The Reliability of Measuring Instruments: Tom Knapp's book on reliability of measurement is freely available on this website. |
| Understanding Factor Analysis: Online textbook providing overview of factor analysis, by political scientist RJ Rummel. |
| Winsteps and Facets Rasch Analysis Software: Software to construct linear measures from ordered qualitative observations. Includes details of training workshops; free student version and manual available for download. |
| Young, Forrest W.: Emiritus Professor of Quantitative Psychology at the University of North Carolina, Chapel Hill. Includes links to the VISta data visualization software, and plenty of resources for ALSCAL multidimensional scaling, including FORTRAN source code. |