"Practitioner research" is an ongoing, reflective process in which inservice teachers (i.e., practitioners) ask questions about their day-to-day teaching practice, develop plans of action to investigate these questions, draw conclusions supported by evidence as they gather, and use what is learned to facilitate changes in their pedagogy. Collaboration can be an integral component of the process as teachers participate in critical reflection within a supportive framework (Anderson, Herr, and Nihlen 2007). This article discusses one teachers' experience as she used practitioner research to explore the use of science notebooks in her third-grade classroom.