Since 2004, the National Institute for School Leadership (NISL) has offered the Executive Development Program (EDP), a leadership program for sitting school principals that is typically delivered in two-day workshops once per month over 12 months. From its inception through 2018, 15,000 principals across 23 states have participated in the EDP. This report presents findings from part of RAND's evaluation of the EDP, focusing on how principals applied their EDP learning and coaching to their work as school leaders. The authors draw on a survey of 172 EDP participants, phone interviews of 74 principals, and nine in-depth case studies to examine what improvement efforts principals with EDP experience attempted in their schools and what strategies they applied to reach their goals. [Additional funding for this report was provided through Department of Education grant, Supporting Effective Educator Development (SEED), awarded in 2015.]