This book examines the benefits of applying the Identity Structure Analysis (ISA) to teacher professional development. At present no government, local authority or school is actively applying Identity Structure Analysis to monitor school improvement: in a profession where turnover is extremely high, ISA is framed as a way for professional development to meet the needs of the specific teacher. Examining idiographic ISA analyses as well as practical advice for implementing professional development programs, the authors scrutinise how ISA can be used in conjunction with mentoring to offset teacher turnover. This practical volume will be of interest and value to scholars and researchers of teacher identity and professional development, as well as researchers and policymakers interested in reducing teacher turnover.