Discusses an adaptive diagnostic test used as part of an instructional program in signed-number arithmetic on the PLATO system. Findings indicated that differences in prior and subsequent instructional methods affected the learning of more advanced materials and produced lower achievement scores on posttests. Thirty-two references are listed. (MER)

A situation in which computer-assisted instruction was combined with teacher-taught classes and computerized diagnostic adaptive testing was examined. The computerized diagnostic adaptive test for pre-algebra signed-number lessons was programmed along with a computer-managed routing system by which examinees were sent to the instructional unit…