Observations in industry show that engineers’ perceptions of design activity tend towards positivistic, rational problem-solving, which is at odds with the nuanced, situated, constructivist nature of observed design behaviour. This paradigmatic mismatch appears to inhibit the ability of engineers to reflect ‘on’ reflecting ‘in’ action, and is apparently formed during engineering design education which, within the UK and commonly elsewhere, is heavily influenced by a positivistic ‘engineering science’ doctrine. In this research natural group design behaviour in engineering design education was explored through detailed observation of undergraduate group-project activity. An analytic framework was formed by three sensitising concepts: design as the resolution of paradoxes, designerly ways of knowing, and design as talk. Key findings conceptualise natural design activity in this setting as a form of constructivist inquiry akin to case study research. Five core activity themes emerged; collecting data, analyzing and interpreting data, identifying themes, theory-building and testing, and telling the story. Students engaged spontaneously in these core activities. Findings were sense-checked from an ontological and epistemological viewpoint, and found to be well-grounded if design is considered from a complexity perspective. Implications are that a radically different pedagogy May be appropriate for engineering design education. Students could significantly benefit from understanding their own design activity as constructivist inquiry, rather than rational problem-solving. Set within a broader education in the ‘philosophy of design’, rooted in a complexity paradigm, students could be better enabled to reflect on their own experiential learning of design. Thus resolving the paradigmatic conflict between perception and practice.