Programed units of instruction designed with four different sequences of characterizations and exemplifications of disjunctive concepts were given to preservice elementary school teachers. Students were tested on three levels of concept attainment, with differences between strategies resulting, as one moves through the levels of cognitive…

Three strategies were used to teach 39 community college students about partition of a set.'' Mean achievement of the Exemplification group on the exemplification test was significantly greater than the average of the means of the Characterization-followed-by-exemplification group and the Characterization-preceded-and-followed-by-exemplification…

The effects of negative instances on the acquisition of the mathematical concepts of commutativity and associativity were examined. Also investigated were possible transfer effects that might result from the use of negative instances. For 64 ninth-grade subjects, results favored the treatments containing mixed instances and supported the transfer…

Examines the development of students' understandings about fractions during six weeks of instruction. Reports that all students possessed informal knowledge disconnected from their knowledge of fraction symbols and procedures and that knowledge of rote procedures often interfered with students' attempts to build on their informal knowledge.…

The effect on student attainment of the number of moves in a concept teaching venture is examined. Results suggest the number of moves in short ventures had little effect on attainment of mathematical concepts. However, performance increased as the number of moves in longer ventures increased. (Author/MK)