Do Final Pitches Measure Fieldwork Grounding? A Multi-Source Validity Audit in a Sustainability Design-Thinking Bootcamp

This study examined the validity of pitch-evaluation scores as indicators of fieldwork grounding in a design-thinking bootcamp. Using a qualitative, multi-source validity audit, it analyzed six international student teams participating in a four-day sustainability bootcamp held in mid-2026 in Khung Bang Kachao, Thailand. Data included team worksheets, final pitch decks, rubric scores from four evaluators, facilitator observation notes, community representative feedback, and post-forum student surveys. A two-sided coding framework assessed artifact-based evidence of insight quality, solution alignment, claim-level traceability to fieldwork, and AI-production markers, alongside rubric-derived evaluation signals. The artifacts were independently double-coded, and the two datasets were integrated in a convergence matrix. Findings revealed a marked disconnect between evaluation outcomes and documented fieldwork: a team whose pitch contained no field-traceable claims received grounding-related scores at least as high as those of all field-grounded teams. At the cohort level, the two most field-grounded teams ranked third and last on composite scores, whereas the two most detached teams ranked first and second. The findings challenge the use of final-pitch rubrics alone as valid measures of fieldwork-based design reasoning. The study recommends incorporating process artifacts, evidence-traceability checks, pre-pitch synthesis materials, formal community participation, and clearer simulation framing into assessment design.