The influence of a design education upon reasoning in response to ill-defined design problems was examined through a comparative protocol study of design and non-design students. A statistical analysis compared distributions of and transitions between the activities naming, framing, moving and reflecting. Design student protocols were characterised by significantly increased activity associated with reasoning between problem definition and solution ideation. In contrast, participants lacking any formal design education or experience indicated significantly increased reasoning towards problem definition, with little evidence of ideation. A subsequent qualitative comparison identifies sketching as a potential driver for both increased solution-focused activity and greater iteration between problem definition and solution ideation. Implications for design ability, sketching and appositional bridge-building between problem definition and solution ideation are discussed.