Source of analogy triggers in design: comparing the impact of external and internal sources across experience levels

Analogy helps designers understand complex design problems and develop potential solutions. Two types of analogies can be employed: internally triggered analogies, which are drawn from a designer’s personal knowledge and experience, and externally triggered analogies, which are inspired by external stimuli. This study explores the effects of external and internal sources, their contribution to idea generation, and their relationship with the designer’s experience level. Design protocols were conducted with eight advanced and eight novice design students. No differences were found between novice and advanced participants in the number of new externally or internally triggered analogies they generated. However, the protocols revealed that advanced participants interpreted external stimuli more effectively within the design context and established deeper connections, whereas novice participants tended to rely on more superficial similarities. Across both groups, higher levels of idea generation were observed in protocols with more analogies. This finding confirms the existing literature’s claim that analogies contribute to idea generation. Furthermore, the nature of the ideas generated differed by experience level. Advanced students produced more unrelated and diverse ideas, whereas novices generated more closely related ideas.