Using simulated item response data, the performance of several "robust" and conventional schemes for ability estimation was evaluated in conjunction with logistic item response theory models (one, two, and three parameter models). The simulated item response data were generated using a model that is more complex than are the usual…

How accurately ability is estimated when the test model does not fit the data is considered. To address this question, this study investigated the accuracy of the maximum likelihood estimator of ability for the one-, two- and three-parameter logistic (PL) models. The models were fitted into generated item characteristic curves derived from the…

In connection with the development of item pools for the Navy's experimental Computerized Adaptive Testing (CAT) system, items in five different content areas (General Science, Paragraph Composition, Word Knowledge, Math Knowledge, and Arithmetic Reasoning) have been calibrated using item response theory (IRT) methodology. Operational Armed…