Professional development at the local level: Necessary and sufficient conditions for critical colleagueship

•Investigation of conditions associated with teachers' in-depth discussions.•Focus on teacher communities of inquiry in a professional development initiative.•Using unique methodological approach: Qualitative Comparative Analysis.•Single purpose was a necessary condition associated with in-depth discussion.•Coach questions and connecting theory and practice were also associated conditions.

This paper examines factors that contributed to critical conversations in teacher communities of inquiry (CI) as part of a statewide professional development initiative in the United States. Based on a three-year mixed method design, we use qualitative comparative analysis to investigate the influence of combinations of conditions on the depth of discussion. Results suggest that there were three conditions associated with the extent to which CI members engaged in discussions with substantive interaction and reflection: a clear purpose, coach questioning, and the connection of theory to practice. The findings contribute to the understanding of effective reform implementation in different contexts.