San Francisco State University, WestEd, and 20+ school districts will collaborate and launch CS4NorthCal to address 2 major challenges in high school computer science (CS) education: (1) a lack of student access to rigorous CS instruction and (2) a lack of gender, ethnic, disability, and racial diversity in high school CS courses. By scaling an effective model for preparation, professional development (PD), and ongoing support for high school CS teachers to improve their CS content knowledge and pedagogical skills, this project will increase rigorous and engaging CS course offerings to all high school students. The percentage of female and URG students in high school CS courses will grow, and these students will gain in-demand skills that allow them to enter the CS workforce. The strategies identified and tested in this project for improving teacher preparation and support will be of broad interest, as school districts throughout the country are facing, or will face, the same problems, as they ramp up their own CS offerings. Over the course of this project, the RPP will serve 200 teachers and support 25,000+ high school students.<br/><br/>The goal of CS4NorthCal is to scale up an effective, evidence-based model for preparation, PD, and ongoing support of high school CS teachers. CS4NorthCal will institute a 3-pronged strategy to prepare and support high school teachers committed to CS education excellence throughout Northern California: (1) Scaling a teacher certification program for CS teacher preparation and PD to increase the number of authorized high school CS teachers. (2) Expanding Professional Learning Communities (PLCs) for newly certified high school CS teachers to provide continuous professional learning on CS curricula and inclusive pedagogical strategies. (3) Establishing and scaling a high school CS teacher mentorship program to offer ongoing, rigorous support to newly certified teachers to improve their retention and skills. The RPP has jointly developed 4 research questions to investigate how best to design certification courses, PLCs, and teacher mentorship programs to prepare teachers of varying disciplinary and geographic backgrounds to teach high school CS equitably: (1) How can online certification courses be designed to effectively prepare teachers with CS content knowledge and skills? (2) How can online certification courses be designed to support teachers in developing culturally responsive and inclusive teaching strategies for CS? (3) How can certification courses and ongoing support be designed to address the needs and readiness levels of teachers with different disciplinary backgrounds? (4) How do teachers engage in ongoing support (e.g., PLCs, mentoring) focused on the continuing development of their content knowledge and culturally responsive teaching skills? This project will contribute critical data to the evidence base for high school CS teacher preparation and support, and the knowledge generated can be used by states across the nation to ramp up their CS offerings and support learning for all students.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.