Background: How can educators and students partner in the work of making transformational changes in schools and school systems? This paper will address how teacher researchers, funded by the Ontario Ministry of Education in Canada, have studied the student experience to generate evidence. It will outline changes in practice and benefits for learning, teaching and leading. The value of teacher research beyond professional learning has often been disputed. The most common criticism of teacher research is that it does not contribute new knowledge. Distinguishing between evidence-based practice and practice-based evidence may clarify how teachers can generate new knowledge that can inform practice and support systemic change. Programme description: This work has been cultivated through a unique programme and was organised across a large jurisdiction. It has supported "study teachers" to engage as researchers in order to generate practice-based evidence and to mobilise knowledge within and across schools and systems. Study description: The study was designed to engage study teachers collaboratively in identifying the essential practices of studying the student experience which might be sustainable outside the structures of the programme. A participatory approach was taken to engaging with study teachers to identify the essential practices of their role as teacher researchers: this was not a study "of" or "about" them. Purpose: The study aims were twofold: (a) to examine impressions of impact reported by study teachers on students, participating study teachers and their teaching colleagues; and (b) to identify the essential practices of the teacher researcher approach to studying the student experience. Methods: A mixed methods approach was adopted to examine evidence of the reported impact of the programme on students and teachers. Data were drawn from: survey responses from study teachers; abstracts of study teachers' work; meeting documents (for example, photographs and documentation of conversations); and products developed by study teachers and their partners (for example, research papers, presentations, posters, infographics, blogs and videos). Findings: Results include an examination of the reported evidence of impact on students' learning, agency and well-being; descriptions of the impact for teachers; and a synthesis of the seven essential practices of the approach. The seven essential practices and corresponding tensions that were identified with the study teachers were as follows: (1) fostering learner agency and negotiating power in the classroom; (2) collaborative learning relationships and sufficient time; (3) systematic pedagogical documentation and robust analysis; (4) generating practice-based evidence and new learning; (5) engaging students and teachers as researchers and negotiating power in constructing knowledge; (6) inspiring pedagogical possibilities and confronting dominant discourses; and (7) sustaining innovation and joy in learning and accepting being uncomfortable with uncertainty. Discussion: This article considers the challenges and possibilities of embedding the practice of studying student learning within regular classroom and school structures in order to support transformational change. It also discusses implications for students and teachers as leaders in transforming schooling, including the potential benefits of extending teacher and academic researcher partnerships.