Characterizing the Effects of Multiple Analogs and Extraneous Information for Novice Designers in Design-by-Analogy

This study examines how the quantity of ideas and analog transfer in design-by-analogy (DbA) are affected by multiple analogs and extraneous information, or noise, using a between-subjects, factorial experiment. To evaluate the effects of multiple analogs and noise on ideation, the study uses two metrics in conjunction with one another; namely, number of ideas (most typical in engineering design) and recognition of high-level principle (more common in psychology). The quantity analysis included three components: number of ideas generated, number of ideas that use example products (analogs and noise stimuli), and number of ideas that use analogs. The results indicate two important findings: (1) providing multiple analogs during ideation had a positive impact on ideation quantity and analog transfer. Specifically, the number of analog-based ideas increased with increasing number of analogs but eventually reached a “saturation point”; (2) introducing extraneous information (noise) diminished the successful mapping of analogs to design solutions. The presence of extraneous information did not significantly affect student designers' ability to identify high-level principles in analogs. The study demonstrated that some extraneous information was perceived as surface similar analogs. Any design analog retrieval method or automated tool will produce extraneous information, and more work is needed to understand and minimize its impact.