When evaluating the effectiveness of professional development in mathematics education, one of the most challenging aspects is finding or developing instruments to measure changes in teachers' content knowledge. Typically, content knowledge in mathematics is viewed rather narrowly as an ability to arrive at an accurate answer to a mathematical problem. Very rarely is there an interest in examining the problem-solving process, including misconceptions and verification, as a pathway to understanding.
This study took an expansive view of mathematical content knowledge and used a variety of data sources that provide a more complete picture of teachers as learners and teachers of mathematics than what could be gleaned from a multiple choice test. In this study, researchers hypothesized that there would be changes in teachers' understanding of big mathematical ideas presented in the course, as well as changes in teachers' productive disposition, engagement in inquiry and reflection, and ability to communicate mathematical thinking.
An extension of the study's claims was that as a result of participation in summer courses, subsequent changes in classroom instruction would become evident through classroom observations.