Online computer science courses, such as those run by virtual public high schools, can help reach students in schools where funding constraints limit student opportunity. Many schools cannot afford computer science teachers, but with virtual course offerings, students can receive the same learning opportunities regardless of physical location or funding limitations. Due to the increasing demand for online programs, there is a similar demand for high-quality online professional development opportunities. While a substantial body of research focuses on online computer science educators identifying current needs in CS education, additional research is still needed to provide strategies that strengthen the effectiveness of online computer science courses.

Through a Research-to-Practice Partnership, this paper examines the effectiveness of a virtual professional development program for online Advanced Placement Computer Science A (APCSA) teachers. This study addresses the following questions: (1) To what extent did the online professional development course improve teacher knowledge in teaching APCSA to high school students? (2) What were K-12 teachers’ perceptions of their experiences from the professional development course? The data collected throughout this study included pre and post-test, course surveys, and asynchronous course discussions. A paired t-test was run using the pre and post-test data to analyze changes to participants’ overall computer science content knowledge. Our findings suggest that our participant’s content knowledge has increased due to our online course. Additionally, the findings from this study shed light on additional ways to support teachers such as offering future professional development opportunities.