I n the summer of 2006, the Green River Regional Education Center (GRREC) in Bowling Green, Kentucky, began an initiative designed to strengthen student performance in mathematics through professional development designed to strengthen the mathematics content knowledge of K-8 teachers in the region. We framed this professional development effort as learning through a "bifocal lens." That is, we wanted participating teachers to learn more mathematics but we also wanted them to be able to think about how they were learning that mathematics and implications for their own teaching practice. The project, called the Math Alliance Initiative, began as collaboration between GRREC and teams of teachers from 48 schools in 17 districts in the region. During the second year of the project, with additional funding through a 3- year Math and Science Partnership grant, the initiative was expanded to include teacher leaders from these participat- ing schools as well. In total, over 220 teachers and teacher leaders from these 17 districts participated over the four years of the project. A number of partners played key roles in the project including the Kentucky Department of Education, Western Kentucky University faculty, Global Education Resources, Measured Progress, and Carnegie Learning, with the GRREC overseeing and coordinating the effort. A number of master practitioners from the region who were experi- enced professional development providers also collaborated with these key partners to design and facilitate the profes- sional development that was offered. Each year, the project offered a 5-day Summer Math Academy during which participants explored mathematics content with a focus on reasoning and sense making. During the school year, the project offered four full days of professional development that focused on implications for instruction, including the use of instructional strategies that supported mathematical reasoning and sense making, as well as the use of formative assessment strategies that provided more information about what students under- stood and where they were struggling and implications of this formative assessment data for instruction. An impor- tant part of this work also involved becoming more articu- late about what we want students to learn at each grade level. The Summer Math Academies and the school-day sessions are described in greater detail below. Summer Math Academies in Years 1 - 3 Summer Math Academies were planned and facilitated by Carnegie Learning and our designated master practition- ers, using pretest and survey data from participants to determine the particular focus of the mathematics that would be addressed. On page 46 is a table that lays out that mathematics content of the Summer Math Academies over the first three years of the project. These summer academies were designed to strengthen and deepen participants’ understanding of mathematics through the use of problem solving activities that built conceptual understanding and increased procedural fluency using tasks that addressed the specified content. This included explo- ration of cognitively demanding tasks created by Carnegie Learning that were intended to address the specified 44 NCSM JOURNAL • FALL 2011 Transformational Professional Development: Teacher Learning Through a Bifocal Lens Janet Lynne Tassell and Hope Marchionda, Western Kentucky University Sandra Baker, Allison Bemiss, Liz Brewer, Kathy Read, and Terri Stice, Green River Regional Education Center Alice Cantrell, Warren County Public Schools Daryl Woods, Franklin-Simpson Public Schools