Professional learning communities (PLC) have been widely accepted as effective with respect to good atmosphere, adequate leadership practices, and functional working practices. However, the outcomes for school improvement depend on case-specific issues. To identify less culturally and contextually bound issues in 3 PLC settings in Canada, Finland, and Israel, we examined our cases through the notion of "collaborativeness". It refers to a systematic and shared process consisting of efforts, ideas, and activities that aim at achieving synergy. By combining the 3 data sets and applying a special model, we were able to distinguish, through qualitative content analysis, ingredients of collaborativeness beyond culture and context that we consider particularly essential. The crucial factor proved to be a dynamic relationship between mutual and deep learning, realized through 5 different ways. We further believe that our results could serve other organizations striving for school improvement in other kinds of cultural and contextual settings.