With support from the Fremont Street Fund, a national nonprofit philanthropy dedicated to catalyzing and scaling educator-led innovation in public schools, the authors of this report embarked on a research effort to understand the underlying causes that drove teachers to adopt new teaching practices--such as blended learning, mastery-based learning, or project-based learning. What they discovered supports the research that we have done in other fields. Teachers, like anyone else, look for better alternatives when the status quo isn't working. They change their habits and behavior when circumstances in their lives cause them to find new approaches to accomplishing the things they are already trying to get done. By understanding these motivations through what the authors call the "Jobs to Be Done" framework, they pieced together four different Jobs that cause teachers to make instructional changes in their classrooms. In essence, different teachers find themselves in different circumstances. Sometimes they want their schools to improve. Sometimes they are looking for practical strategies and tools to make the classroom experience more engaging. Sometimes they struggle with feeling powerless to meet the individual needs of every student. And sometimes they want to keep from falling behind on a school-wide initiative that has little appeal to them otherwise. This paper is a guide for any school leaders, district administrators, technical assistance providers, policymakers, and foundations whose reform initiatives hinge on whether teachers decide to embrace new practices. This report offers an overview of the Jobs to Be Done framework, then dives into the authors' research findings and recommendations. [This research was made possible by a generous grant from Fremont Street.]