eCAT-Listening: design and psychometric properties of a computerized adaptive test on English Listening.

In this study, eCAT-Listening, a new computerized adaptive test for the evaluation of English Listening, is described. Item bank development, anchor design for data collection, and the study of the psychometric properties of the item bank and the adaptive test are described. The calibration sample comprised 1.576 participants. Good psychometric guarantees: the bank is unidimensional, the items are satisfactorily fitted to the 3-parameter logistic model, and an accurate estimation of the trait level is obtained. As validity evidence, a high correlation was obtained between the estimated trait level and a latent factor made up of the diverse criteria selected. The analysis of the trait level estimation by means of a simulation led us to fix the test length at 20 items, with a maximum exposure rate of .40.