81 Evaluation of MCD sessions in what circumstances do sessions prove fruitful? This might differ per team; for some, it might not be the right time (yet) to start or continue with MCD. Or some teams may be better supported by another conversation method than the one we used in this study. A continuous evaluation with attention to shared ownership of MCD is of great importance (Hartman et al., 2016), to keep all stakeholders connected and to make MCD sessions fruitful. Finally, in future studies on moral challenges for prison staff, it would be worthwhile to analyze whether there is a decrease of moral distress experiences by prison staff after implementing MCD. STRENGTHS & LIMITATIONS It is the first time an evaluation study has been performed with prison staff on an ESS, particularly MCD; hence, we gained new insights into the value of MCD for them. The mixed methods design made it possible to complement and enrich evaluative scores with qualitative insights. Compared to current MCD evaluation studies, we present a study with a high number of sessions and high response rates. Although many results show positive evaluations, we highlighted lower scores since we wish to learn from them. In the single-MCD-evaluation forms not all questions were formulated neutrally; instead, questions were asked about, e.g., what part of the experience should be improved. Using both the regulated and responsive approach in our research design created tensions. E.g., our goal of having a series resulted in asking teams to plan 10 MCD sessions in a year, however, this made some participants experience an involuntary participation in MCD. Hence, we could not always be responsive to their needs in having e.g., less sessions or using another MCD conversation method. However, our responsive approach did promote the ownership of MCD for staff, and team members were involved in resolving planning issues and were part of steering committees. 3