Online professional development (online PD), the acquisition of new skills and knowledge related to the teaching profession via the Internet, is an emerging field for teachers. This mixed- methods research explored the impact of an online PD program on high school teachers’ self-efficacy levels, classroom instruction, and the role that school culture played on teachers accepting or rejecting the online PD. Within a social cognitive theory lens, this study helped frame teacher attitudes and adult learning in the context of school culture.

Phase 1 of this study used quantitative data from two surveys called PRE and POST, which were taken before and after the online PD program, respectively. Qualitative data were collected in Phase 2, using the International Society for Technology in Education Classroom Observation Tool (ICOT), participants’ journal reflections, and interviews. Findings indicated statistically significant changes in self-efficacy levels for eight of the 21 survey items and minimal changes in technology use during instruction. Furthermore, various aspects of school culture independently affected teachers’ inclination to accept or reject the online PD. Findings supported the concept of designing personalized professional development programs tailored to the individual’s specific learning styles, attitudes, and experiences of school culture.