This study addressed the problem of chronic low student achievement in language arts at a Program Improvement 5+ school by implementing two cycles of facilitated lesson study. Using action research to facilitate and monitor change in instructional practices at a school that is currently undergoing a teacher-initiated turnaround reform effort, this study put into practice a facilitation model with lesson study cycles with teachers in the third, fourth, and fifth grades. As facilitator and content expert, I guided teachers through the elements of lesson study including: (a) defining and problem, problem analysis, and goal setting; (b) designing and planning a lesson; (c) implementing, teaching, and observing the lessons; (d) evaluating and reflecting on lessons while analyzing student work; (e) revising and improving the lesson; (f) reteaching the revised lessons; and (g) re-evaluating the retaught lesson and analyzing student work for the second time. Through facilitating the lesson study cycles, I analyzed the process of teacher collaboration, changes to pedagogical practices, impact on student achievement, and the value of lesson study. Teachers reported an increase to their instructional capacity following the intervention. Teachers were able to engage in focused planning and develop explicit instruction and attend to student learning, and began to perceive themselves as facilitators of instruction. Teachers found that the lesson study process increased their motivation and confidence as educators. Further, the study found that the intervention impacted student learning through increased student achievement scores in the targeted standards and in the quality of writing. Lesson study, as a professional development model, was reported to provide consistency, accountability, and a safe environment for teachers. Teachers also reported that they valued the collaboration and cross-grade level articulation through the lesson study process. The study provides implications for other high-stakes accountability schools with chronic low student performance to change, build, and sustain the instructional capacities of teachers to impact student achievement. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]