Background: Bringing about conceptual change in school science classrooms is difficult for teachers. Researchers in this field have struggled to influence classroom practice. Purpose: The present research presents a method and a framework for video-based pedagogy analysis. Sample: Six groups of 11-year-old pupils took part (three girls and three boys) in each expert micro-teaching interview, led by a science specialist (Advanced Skills Teacher). A 'Concurrent Verbal Protocol and Retrospective Debriefing' interview happened with the teacher approximately one month later. Six teachers and thirty-six pupils participated altogether. Design and method: Three research methods (expert microteaching, verbal protocols and retrospective debriefing) were used. Data were video-recorded and managed using NVivo. About fifteen hours of video data were analysed using grounded theory methods. The interpretivist theoretical perspective (symbolic interactionism) was underpinned by a social constructionist epistemology. What can be considered evidence is inevitably affected by the researcher's methodological position. So what constitutes reliable evidence can be contentious. Appropriate criteria for evaluating the grounded theory emerging from this study were used. Interpretivist approaches for investigating conceptual change in school science are necessary to complement positivist literature. This approach, proved successful in other fields, is new to this context. Data were recorded in 2013. Results: Findings are presented as a Pedagogy Analysis Framework which uses the concepts: means (including information, misinformation and disinformation), strategy (on a spectrum from micro-strategies, through tactics to macro-strategies;), ends (physical changes, individual mental changes and group mental changes), and accidents. Conclusions: The method allows teachers to help the researcher understand incidents in video-data that are not evident to any external observer. The framework could help strategic dialogue between teachers, student teachers, mentors, teacher educators, and educational researchers.