The POWERSOURCE[c] intervention is a generalizable and powerful formative assessment-based strategy that can be integrated with any ongoing mathematics curriculum to improve teachers' knowledge and practice and, in turn, student learning. Our primary research objectives are based on our hypotheses that as a result of POWERSOURCE[c], teachers will become more proficient in their subject matter knowledge, more skilled in their formative use of assessment, and better focus their instruction on key ideas. Ultimately, teachers will be more effective in helping students to improve their understanding--as shown by measures of student learning. This report provides a detailed overview of our study results from the 2006-07 school year. We found that a knowledge mapping task and a student response analysis task, could be used as a set, or the knowledge mapping task could be used separately from the other tasks, in order to efficiently investigate both content knowledge of teachers and knowledge of teaching algebra. Appendices include: (1) Additional Item Analysis Results; (2) 6th Grade, Teacher Handbook, Properties of Arithmetic: The Distributive Property; (3) Sample Alternative Professional Development Materials; (4) Examples of Professional Development Website Materials; (5) Transfer Measure Items and Sources; (6) Transfer Measure Alignment: Standards and Focal Points; (7) Teacher Surveys; and (8) Interview and Observation Measures. (Contains 1 footnote, 8 tables, and 4 figures.)