This Small Business Innovation Research Phase II project seeks to build a system called CyberCollage as a Social Cyberlearning tool to support computational thinking in STEM education. CyberCollage will enable collective programming of educational games and STEM simulations through a unique combination of networked real-time collaboration mechanisms and Web-based social end-user programming. For example, multiple students can work together on a Frogger game. While one student may be programming the frog, a different student might be working on the turtles. Similarly, students can collaborate on science simulations that explore STEM related questions such as "can your frog live in my pond"? Phase I established technical feasibility, and showed that complex science simulations with tens of thousands of agents can both run efficiently and be created collaboratively by students working together, locally, in the same classroom, or separated by hundreds of miles. Phase II will establish CyberCollage as a scalable cloud-based implementation of a Social Cyberlearning tool, and will integrate embedded assessment mechanisms that make learning outcomes in computational thinking both measurable and predictable. These assessment mechanisms enable the investigation and study of computational thinking transfer evidence between game and STEM applications. The 2010 PCAST report asserts that computational thinking is one of the fundamental concepts of networking and information technology. Fluency in computational thinking is needed to prepare today?s students to be the next generation of innovators and professionals. The proposed combination of high accessibility through Web interfaces, increased motivational prospective through social interfaces, and tested curriculum integrated into required computer education middle school courses is likely to reach a vast audience and attract both women and underrepresented communities to information technology courses and fields. This reach is enhanced by the participation of the National Center of Women in Technology (NCWIT) and Google in the Phase II advisory board. Both organizations are already disseminating AgentSheets Inc. computational thinking resources, which is an extremely positive indicator of a high probability of broad impact and commercial success. The CyberCollage project has established access to disadvantaged communities that include inner city, remote rural, and Native American schools in Alaska, Colorado, South Dakota, Texas and Wyoming. These and other schools will serve as testbeds. A pledged investment by a third-party organization should establish a consumer-oriented extension of CyberCollage, making Social Cyberlearning of computational thinking relevant beyond its original scope of educational applications.