This study examined whether the item response curves from a two-parameter model reflected characteristics of the mathematics items, each of which required unique cognitive tasks. A computer program performed error analysis of test performance. Cognitive subtasks appeared to influence the slopes and difficulties of item response curves. (GDC)

The use of restricted item response models to test hypotheses regarding item difficulty ordering and slope uniformity was demonstrated in a study in which 597 algebra students were asked to solve word problems reflecting various types of cognitive processing. Benefits and limitations of the procedures are discussed. (SLD)

The 63 items on skills in acquiring and using information from written documents contained in the Survey of Young Adult Literacy in the 1985 National Assessment of Educational Progress are analyzed. The analyses are based on a qualitative cognitive model and an item-response theory model. (TJH)