Reflection on practice (ROP) serves to support teachers that introduce innovative instruction into their classrooms. There is an inherent dilemma between competing goals in ROP workshops: developing teachers' skills as reflective practitioners (process), vs. developing specific favored practices (result). This dilemma affects the evaluation of such workshops, as evaluation methods should align with the goals. In this paper we will gain insight on how to resolve the dilemma from the perspective of teaching scientific problem solving, where a similar dilemma between process and result is sharply manifested and thoroughly explored. Assessment methods and tools derived from this perspective were applied in a formative evaluation of a workshop for high school physics teachers. We will show how these analysis tools enabled us to identify differences in outcomes between versions of yearlong workshops   that used different approaches to guidance of ROP. Our research can contribute to the planning and evaluation of ROP workshops.