SCALE-UP (Student-Centered Active Learning Environment with Upside-Down Pedagogies) (Beichner et al., 2007) is a reformed pedagogy and classroom design originally developed for large enrollment university physics courses at North Carolina State University. It is currently being used at over 250 institutions worldwide and has since expanded into other content areas. This exploratory case study examines how classroom, departmental, institutional and cultural factors have caused the reform to evolve over three generations of implementation from its development site to a well-known American implementation and a site in Singapore. A mixed methods study using interviews and class observations reveal the implementation process follows an iterative version of Rogers' (2003)--Innovation in Organizations? model, as institutions re-invent and refine the reform to adapt to their institution. The findings suggest some changes ensure the survival of the reform, for example, adjusting instruction to fit available resources or student learning styles. However, many modifications shift pedagogy toward traditional instruction, potentially decreasing the reform's intended benefits. Awareness of this tendency could help researchers, curriculum and professional development developers and future implementers better support sustainable and effective use of research-based pedagogies.