Expert vs. novice: Problem decomposition/recomposition in engineering design

The purpose of this pilot research was to investigate the differences of using problem decomposition and problem recomposition among dyads of engineering experts, dyads of engineering seniors, and dyads of engineering freshmen. Fifty participants took part in this study. Ten were engineering design experts, twenty were engineering seniors, and twenty were engineering freshmen. All participants completed the same engineering design challenge within an hour. The entire design process was video and audio recorded. After the design session, members participated in a group interview. This study used protocol analysis as the methodology. Video and audio data were transcribed, segmented, and coded. Two coding systems including the FBS ontology and “levels of the problem” were used in this study. A series of statistical techniques were used to analyze data. Interview data and participants' design sketches were used as supplemental data to help answer the research questions. By analyzing the quantitative and qualitative data, it was found that students used less problem decomposition and problem recomposoition than engineer experts in engineering design. This result implies that engineering education should place more importance on teaching problem decomposition and problem recomposition. Students were found to spend less cognitive effort when considering the problem as a whole and interactions between subsystems than engineer experts. In addition, students were also found to spend more cognitive effort when considering details of subsystems. These results showed that students tended to use dept-first decomposition and experts tended to use breadth-first decomposition in engineering design. The use of Function (F), Behavior (B), and Structure (S) among engineering experts, engineering seniors, and engineering freshmen were compared on 3 levels. Level 1 represents designers considering the problem as an integral whole, Level 2 represents designers considering interactions between subsystems, and Level 3 represents designers considering details of subsystems. The results showed that students used more “S” on Level 1 and 3 but they used less “F” on Level 1 than engineering experts. The results imply that engineering curriculum should improve the teaching of problem definition in engineering design because students need to understand the problem before solving it.