Citation: Dixon, R., & Johnson, Scott. (2011). Experts vs. Novices: Differences in How Mental Representations are Used in Engineering Design. Journal of Technology Education, 23(1), 47–65.
Summary: An expert/novice difference study looking at engineers' problem-solving approaches. Experts rarely used propositions or analogies in the problem space. They tended to quickly explore the solution space and used formulas and heuristics.
- Studies propositions, metaphors, and analogies were examined. Looked at the mental representations of students and professional engineers when they solved an engineering design problem.
- Three Juniors and three seniors. They were exposed to engineering design elements in their courses.
- Four professional engineers had a degree in mechanical engineering and had worked as a mechanical engineer between seven and forty years.
- From Cross (2004): Expert designers
- Name: select features of the problem space to which they chose to attend.
- Frame: identify areas of the solution space they chose to explore.
- Stayed on their principle solution concept as long as possible, but abandon them when the cognitive cost for abandoning them become too high.
- Use non-linear problem-solving strategies. Interleave specifying the problem with developing the solution. Mix breadth-first with depth-first approaches.
- Alternate rapidly between modes of activity to make novel decisions.
- Maintain openness, ambiguity about features and aspects of the design.
- Rely on first principles in origination and developing concepts.
- Creative solutions arise when a conflict between problem goal and criteria for a solution exist.
- Experts are domain specific. An expert in one domain doesn't make you an expert in another.
- Study looked at expert/novice differences in how people use propositions, metaphors, and analogies to solve engineering design problems.
- Frequency of propositions, metaphors, and analogies.
- Attributes of propositions, metaphors, and analogies.
- Subjects did think aloud protocols.
- The use of mental representations (propositions, analogies, and metaphors) is important in engineering design.
- Experts rarely employed propositions or analogies in their problem space.
- Experts are different from novices in their use of within-domain analogies, between-domain analogies, heuristics, and formulas.
- Experts' general experience and confidence caused them to immediately start exploring the solution space. Novices tended to spend more time in a problem-identifying mode than a problem-solving mode.
- Experts used formulas and heuristics equally and novices relied more on heuristics.
- Authors recommend exposing students to a wide variety of design examples, and making active comparisons, critiques, and evaluations to understand the underlying concepts that make certain designs similar or different.