Numerous researchers have investigated distance education in postsecondary settings, but there is a paucity of research regarding the design and delivery of online professional development for K-12 educators. The goal of this mixed methods sequential exploratory study was to examine attitudes of middle grades educators toward an online professional development course held for teachers employed by one suburban school district in the southeast region of the United States. The theoretical framework is Knowles's theory of adult education (andragogy). The research questions addressed perceptions of connectedness and learning in an online professional development course. A structured interview protocol was used to collect qualitative data from 5 participants; data were coded and analyzed into 6 typologies. The Classroom Community Scale (CCS) that assessed perceptions of (a) connectedness and (b) learning effectiveness among 23 participants provided quantitative data to complement the interview findings. Mean ranks were used to prioritize 10 items within each of the 2 CCS subscales. Overall, participants felt like they could rely on others in the course yet were uncertain that others could depend on them. The study also identified a preference for immediate feedback and activities that required collaboration. These findings can be used to inform the design of online professional development courses for K-12 educators. This study contributes to positive social change by showing that online opportunities may allow teachers to collaborate with colleagues without the restrictions of time and travel by creating a community of learners through Web 2.0 tools. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]