Building Sustainable STEM Research Partnerships: A 20‐Year Case Study of University–K‐12 Collaboration Through an Intermediary Organization

ABSTRACT This qualitative case study examined how the Center for Science and the Schools (CSATS), a university‐based intermediary organization, sustained partnerships between STEM researchers and K‐12 educators over 20 years (2004–2024). Data were collected through surveys of 21 STEM research faculty across 16 disciplines, 11 current and former CSATS personnel, evaluations from 477 teachers, and eight archival documents spanning CSATS' history. Reflexive thematic analysis revealed a triadic partnership model in which science education faculty with dual expertise mediate between disciplinary researchers and classroom teachers. Rather than simplifying research content, the translation process centers researchers' discipline‐specific epistemic practices, identified through structured elicitation using the MASTER Model and formalized in the TEACHER framework. Researcher satisfaction was uniformly high across all partnership dimensions ( M = 4.82–5.00 on a 5‐point scale), and partnership durations ranged from single grants to 17 years. All 21 researcher respondents characterized the complementary expertise of CSATS faculty as essential, with most stating the work would not have been possible without the intermediary. Findings also revealed a sustainability paradox in which demonstrated effectiveness at the partnership level coexists with chronic institutional vulnerability at the organizational level, suggesting that universities benefiting from research impact infrastructure must invest in sustaining it.