The impact of receiving the same items on consecutive computer adaptive test administrations

This study addresses item exposure in a Computerized Adaptive Test (CAT) when the item selection algorithm is permitted to present examinees with questions that they have already been asked in a previous test administration. The results indicate that the combined use of an adaptive algorithm to select items and latent trait theory to estimate person ability provides substantial protection from score contamination. The implications for constraints that prohibit examinees from seeing an item twice are discussed.