Much previously published material for estimating the reliability of classification has been based on the assumption that a test consists of a known number of equally weighted items. The test score is the number of those items answered correctly. These methods cannot be used with classifications based on weighted composite scores, especially if…

The Association of American Medical Colleges is conducting research to develop, implement, and evaluate a Medical College Admission Test (MCAT) essay testing program. Essay administration in the spring and fall of 1985 and 1986 suggested that additional research was needed on the development of topics which elicit similar skills and meet standard…

The sampling errors of maximum likelihood estimates of item-response theory parameters are studied in the case where both people and item parameters are estimated simultaneously. A check on the validity of the standard error formulas is carried out. The effect of varying sample size, test length, and the shape of the ability distribution is…