Twenty years of online teacher communities: A systematic review of formally-organized and informally-developed professional learning groups

This paper presents a systematic review of 52 empirical studies of formally-organized and informally-developed online teacher communities from the early 2000s to the present time. Focusing on the social as well as technological aspects of online participation, the review explores how teacher communities are shaped by broader contexts of teaching. The review shows that while formally-organized and informally-developed communities address different needs amongst teachers and support different outcomes, they also share several common characteristics. Indeed, regardless of type, online communities can be a valuable means of developing supportive and collegial professional practices. That said, more evidence is required on the specific collaborative merits of teachers' online interactions.