93 Defining and measuring moral craftsmanship of prison staff, and funded our research to explore the concept of MCS and develop a related questionnaire. METHODS Explorative literature study We started with a document study based on material provided by the DCIA, to gain an understanding of what MCS could and should consist of within their organization. At the same time, in sessions in which all authors participated, existing concepts from the field of professional and empirical ethics from the literature were selected based on their relatability to MCS: concepts such as normative professionalism, moral competency, moral sensitivity, moral decision making, moral attitude, moral leadership. Then, we continued with an explorative literature search regarding relevant concepts. Furthermore, we explored existing questionnaires related to the concepts and recorded the used domains. Identification and selection of conceptual elements All insights from the explorative literature and DCIA documents helped to identify relevant elements of the concept of MCS. From these sources, we produced a first mind map of MCS elements. Some existing questionnaires on related concepts already included domains of elements, which we gathered. We reached a consensus on which elements were relevant for MCS. The selected elements of MCS in our mind map were placed in three levels (individual, team, leadership), inspired by existing literature. Next, we strived to find a subdivision and titles for the domains that would cover and clearly reflect all conceptual elements. This was done through a thematic content analysis, summarizing the variation and regularities in the data (Green & Thorogood, 2013). After the involvement of all authors in all adaptation rounds, we reached a consensus about the subdivision levels of all MCS elements. The triangulation of researchers in this last step generated reliability and credibility (Green & Thorogood, 2014). Development of the MCS definition During the research, insights about the meaning of MCS continued to develop. Finally, the literature study and the DCIA documents inspired us to bring existing definitions of related concepts together to arrive at the definition of MCS. We pursued consensus among all authors during rounds of adaptations, to come to the final version of the 4