Ms. Anderson leads a study group involving two groups of middle school mathematics teachers who increase their knowledge of mathematics, improve their assessment of student learning, and improve the quality of their lessons. Through two lesson study groups, teachers work to improve the teaching of fractions and probability. As a result of the improved lessons, students better understand how to retain the material and apply what they have learned to new situations. Lessons are videotaped for further review and, to measure success, students collect samples of their work for self-assessment in a personal portfolio. After the project is completed, participants share their findings with the district’s Math Forum and at various conferences.