Many academic tests (e.g. short-answer and multiple-choice) sample required knowledge with questions scoring 0 or 1 (dichotomous scoring). Few textbooks give useful guidance on the length of test needed to do this reliably. Posey's binomial error model of 1932 provides the best starting point, but allows neither for heterogeneity of question…

Empirical results are presented as regards the implementation of a latent-trait psychometric model by means of conditional maximum likelihood estimation. Items are scored polychotomously into varying numbers of nominal categories and the test and item characteristic curves and information functions are examined. It is concluded that scoring items…

This is a final report of support received through the National Institute of Education (NIE) to assist in research on the writing ability of United States children. The study began under the auspices of the International Association for the Evaluation of Educational Achievement (IEA) in order to contribute to a cross national assessment of…