An adaptive testing method is presented that controls the speededness of a test using predictions of the test takers' response times on the candidate items in the pool. Two different types of predictions are investigated: posterior predictions given the actual response times on the items already administered and posterior predictions that use the…

The use of computers to build diagnostic inferences is presented in two contexts: (1) closed world, exemplified by the space shuttle launch monitoring system; and (2) open world, represented by computerized diagnostic testing of reading comprehension. The analysis shows that the closed world provides a substantially cleaner environment within…