Assessing Digital Circuit Design. Final Report.

The focus of this project was on characterizing and assessing design problem solving in the area of digital circuit design. Think-aloud protocols and computer traces of subject problem-solving behavior were used to elucidate the cognitive processes involved in designing combinational and complex sequential circuits by: (1) studying the differences between two experts and five intermediates in solving combination circuit problems; (2) characterizing planning behavior and its impact on the quality of solutions of 20 subjects for combinational circuits; (3) validating the effectiveness of traces collected by a design tool by two raters in assessing problem-solving behavior for combinational circuits; and (4) characterizing and assessing problem-solving behavior of 11 subjects designing complex sequential circuits. The combinational circuit studies revealed local planning in problem solving but little global planning, and clear differences between intermediate and expert problem solving did not emerge. On the other hand, the complex sequential circuit design problems revealed significant differences between expert, intermediate, and novice problem solvers. Problem solving was successfully modeled by integrating problem decomposition, transformation and iterative refinement, and analogy/prototype models. (Contains 8 tables, 3 figures, and 20 references.) (Author/SLD)