Abstract Iterations in the early stages of design can stagnate, reducing final concept quality; however, it is hard to identify these critical moments. We propose a diagnostic framework that identifies stagnation, defined as the absence of substantive changes in problem framings or solution ideas across consecutive phases, by visualizing their substantive changes/non-change as trajectories. We analyzed data collected across five-month design thinking projects, combining the visualization of 31 teams created using the framework and post-project interviews with 24 participants. Statistical analyses showed that stagnation in the problem framing was closely associated with lower creativity. A lack of change in both problem framing and solution ideas indicated a breakdown in interconnected activities between problem formulation and solution development, whereas changes in solutions alone indicated entrenchment in a single problem framing. Teams that revised both yet produced low-creativity outcomes focused disproportionately on problem-definition activities rather than solution evaluation. Teams with fixed framings but evolving solution ideas recognized the need for change yet were unable to abandon prior commitments. The proposed framework enables early detection of stagnation, allowing instructors and teams to intervene before it undermines design outcomes.
Ito et al. (2026) studied this question.