Affinity spaces are digital or physical spaces in which participants interact with one another around content of shared interest and through a common portal (or platform). Among teachers, some of the largest affinity spaces may be those organized around hashtags on Twitter: These spaces are public, largely unmoderated, and thriving, yet very little is known about them, especially those based in geographical areas such as American states. This paper examines these potential affinity spaces by providing the first large-scale study of them in the form of an examination of 47 State Educational Twitter Hashtags (SETHs). Collecting over 550,000 tweets over 6 months, our analysis focused on who is participating in SETHs, how active participants are, and when participation occurred. We found support for two of Gee’s tenets of affinity spaces, in particular many interactions through a shared portal. Though the content of tweets were not the focus, this study’s findings lend support to efforts to identify which particular SETHs will be best suited to subsequent analysis of their content and what times subsequent analysis might most productively focus on. We discuss implications for how we conceive of teacher professional development and suggest directions for future research focused on the content of tweets associated with SETHs.

Twitter is increasingly accepted as an important educational technology and has been shown to serve a range of purposes. In fact, this variety suggests that Twitter has the potential to serve as a foundational technology: one capable of supporting teachers’ learning across multiple formal and informal contexts. To explore this possibility, we examined the purposes that Twitter serves in one educational technology graduate program. We collected over 9000 tweets containing any of 12 program-related hashtags and coded a sample of them to describe the purposes they served. This resulted in six themes: contribute to disciplinary conversation, engage with disciplinary conversation, build community, make connections with other communities, ask for and provide support, and unclear or irrelevant purpose. These themes—and the varied contexts they were associated with—suggest that Twitter serves as a foundational technology in this program and has the potential to do so in other educational communities.