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…

This study used a series of simulations to answer questions about the efficacy of adaptive testing raised by empirical studies. The first study showed that for reasonable high entry points, parameters estimated from paper-and-pencil test protocols cross-validated remarkably well to groups actually tested at a computer terminal. This suggested that…

The purpose of the present research was to study, systematically, the "goodness-of-fit" of the one-, two-, and three-parameter logistic models. We studied, using computer-simulated test data, the effects of four variables: variation in item discrimination parameters, the average value of the pseudo-chance level parameters, test length,…

The impact of overall test length and difficulty on the expert judgments of item performance by the Nedelsky method were studied. Five university-level instructors predicting the performance of minimally competent candidates on a mathematics examination were fairly consistent in their assessments regardless of length or difficulty of the test.…