Constraints on the abstraction of solutions.

Students in college algebra classes attempted to solve a series of three mixture problems and three distance problems and to match concepts between the first two problems in a series. The detailed comparison of two isomorphs did not result in the abstraction of a solution schema, as it was found to do by Gick and Holyoak (1983) for convergence problems. Attempts to promote abstraction by not allowing students to refer to a specific analogue (Experiment 2) and by providing information about corresponding concepts and principles (Experiment 3) were unsuccessful. These findings suggest that the bottom-up, similarity-based approaches encouraged by mapping concepts may need to be supplemented by top-down, principle-driven instruction