Cognitive diagnostic models (CDM) have been around for more than a decade but their application is far from widespread for mainly two reasons: (1) CDMs are novel, as compared to traditional IRT models. Consequently, many researchers lack familiarity with them and their properties, and (2) Software programs doing CDMs have been expensive and not…

On the occasion of Psychometrika's fiftieth anniversary, the past twenty-five years' developments in mental test theory are reviewed. Psychometrika articles treating topics in test theory are listed in a bibliography. (Author/LMO)

The simple practice effects commonly observed when retaking general cognitive ability tests present a potential paradox. If observed score changes reflect real changes in g, we must revisit our understanding of its stability. Conversely, if observed score changes reflect something other than a true change in the underlying latent construct, this…

Tracing the development of the Otis test series, the author argues that there will be a continuing demand for group-administered general mental ability tests in education. He foresees a need for better ways of relating ability test scores with skills and achievements to make them more educationally useful. (Author/JAZ)