“…This observational study analyzes public data from three purposefully selected hashtag-based AP Biology Twitter teacher communities ( #apbiochat, #apbioleaderacademy, #apbioleaderacad ). Findings of a study that distributed web-based surveys to all AP Biology, Chemistry, and Physics teachers in the nation informed the selection process (Fischer, Eisenkraft, Fishman, Hübner, & Lawrenz, 2018; Fischer et al, 2016; Fischer, Fishman, et al, 2018; Fischer, McCoy, Foster, Eisenkraft, & Lawrenz, 2019). The survey asked teachers to describe their PD participation in face-to-face and online settings.…”