A model for the age standardization of test scores is presented, which is fitted to the percentile points of the raw score distribution and assumes a linear trend of each percentile with age. The model's applications in standardizing tests and diagnostic plots produced by a computer program--STANEW--are described. (SLD)

The form of item log-likelihood surface was investigated under two-parameter and three-parameter logistic models. Results confirm that the LOGIST program procedures used to locate the maximum of the likelihood functions are consistent with the form of the item log-likelihood surface. (SLD)

Extensions of unidimensional appropriateness indices are developed for multiunidimensional tests (multidimensional tests composed of unidimensional subtests). Simulated and real data (scores of 2,978 students on the Armed Services Vocational Aptitude Battery) were used to evaluate the indices' effectiveness in determining individuals who are…

The importance of regression diagnostics in detecting influential data points is discussed, and five statistics are recommended for the applied researcher. The suggested diagnostics were used on a dataset of 24 subjects, and effects were analyzed. Colinearity-based diagnostics and diagnostics for a variety of procedures are discussed. (SLD)

A theoretical framework for mastery testing based on item response theory and Bayesian decision theory is described and illustrated. Implementation depends on the availability of (1) a computerized test delivery system; (2) a pool of pretested items; and (3) a model relating observed test performance to true mastery status. (SLD)