Experts and novices: Differences in their use of mental representation and metacognition in engineering design

Research shows that mental representation such as analogical reasoning is a fundamental cognitive tool for design problem solving (Daugherty & Mentzer, 2008; Hey, Lensey, Agogino, & Wood, 2008; Lewis, 2008). Not much is known, however, about the way students and professional engineers actively generate and change their mental representation when solving a engineering design problem. There are very few studies that show how different types of mental representations; such as metaphors, propositions, and analogies; interplay with higher order cognitive processes; such as planning, monitoring, and evaluation; as engineering designers navigate their problem and solution spaces. This empirical study investigated the mental representation and metacognitive regulation of student and professional engineers while they solve an engineering design problem. The intent is to gain a deeper insight in the differences that exists in the cognitive process of engineering students and professional engineers. The research questions guided this study were (a) How do the mental representations (propositions, metaphors, and analogies) of student and professional engineers differ in their problem and solution spaces in terms of their frequency, types, and attributes? (b) How does the metacognitive regulation (planning, monitoring, and evaluation) of student and professional engineers differ in their problem and solution spaces in terms of their frequency and characteristics? and (c) How do the mental representation and metacognitive regulation of students and professional engineers relate to their overall engineering design strategy? Concurrent and retrospective verbal protocols were collected from six mechanical engineering students and four professional mechanical engineers as they solved an engineering design problem. Their verbalizations were audio recorded, transcribed, and coded. The conclusions drawn from the data were: the use of mental representations such as propositions, analogies, and metaphors by experts and novice engineering designers in the different mental spaces are important in engineering design. Expert engineering designers use analogies differently in their solution space than do novice engineering designers. Expert engineering designers rely on within-domain analogies, between-domain analogies, heuristics, and formulas differently from novice engineering designers. In engineering design evaluation plays a larger role in the solution space of expert designers while novice designers tend to do more planning in the problem space. Finally, based on the findings recommendations are provided for engineering and technology education curriculum and instruction, engineering practice in industry, and for future research