Detection of Known Items in Adaptive Testing with a Statistical Quality Control Method

response theory, parameter drift Due to previous exposure of items in adaptive testing, items may become known to a substantial portion of examinees. A disclosed item is bound to show drift in the item parameter values. In this paper: it is suggested to use a statistical quality control method for the detection of known items. The method is worked out in detail f in the I-PL attd 3-PL models. Adaptive test data are used to re-estimate the item paranteters, attd these estimates are used in a test of parameter drift. The method is illustrated in a mmtber of simulation studies, including a power study. One of the major problems in computer adaptive testing (CAT) is security. If adaptive testiqg items are administered to examinees on an almost daily basis, alter a while, some items may become known to new examinees. In an attempt to reduce the risk of overexposure several exposure control methods have been developed. These procedures have in commoq that they prevent he items from being administered more often than desirable. Typically, this goal is reache