This paper reports how a teacher–researcher partnership examined a biology teacher's existing pedagogical practices. Furthermore, the paper attempted, through a task design innovation, to create the circumstances under which more interactive and emergent assessment for learning practices could flourish in her classroom. This work involved the use of digital video playback technology as the trigger or catalyst for reflection on concrete experiences by the teacher and her students to occur. Results suggest that the digital video innovation brought about changes in student–teacher interactions in science practical work and assisted the teacher in reflecting on her professional learning.