The California History-Social Science Project (CH-SSP), a legislatively-mandated professional development program is administered out of the University of California, Office of the President. The Executive Offices are based at UCLA, and oversee 17 local sites across California. As part of its mission, CH-SSP engages teachers in action research on the use of technology based discourse tools to support the development of a discipline based reflective thinking process, which promotes student ability to engage in historical thinking and understanding. This action research project grew out of a previous project in 1999 and 2000 in which teachers explored the uses of technology in K-12 history classrooms and developed lessons plans for statewide distribution. Although it was felt that the work which emerged from that project was of a high quality, teachers did not seem to be exploring the issues involved in technology and the classroom at the depth that the researchers were interested in. The program was modified in two ways. Instead of being asked to generate lesson plans, teachers were asked to engage in action research in the classroom. It was felt this methodology was more likely to get teachers to think about their teaching in a reflective manner. The second change was the stronger focus on online discourse tools. So in 2001, 26 teachers from across California conducted research in grade 3-12 classrooms with diverse student populations, low performing and ESL students. The collective results of these research studies were surprisingly uniform. Students, particularly low performing and ESL students, engaged in significantly higher levels of discourse than in the traditional classroom; and they were either learning to engage in or engaging in discipline based activities. The interaction of these two--discourse and activities--lead to higher levels of historical thinking and understanding, as reported by the teachers. This result was only true when the teachers provided scaffolding in the form of discourse supports. (AEF)