The paper reports qualitative findings from a study about how science teachers enacted discursive purposes and talk moves to support the students' experiments. Science teachers may have difficulties assisting students in designing and conducting valid and reliable experiments as the core epistemic practice of science teaching and learning. It is…

Triadic dialogue, the Initiation, Response, Evaluation sequence typical of teacher /student interactions in classrooms, has long been identified as a barrier to students' access to learning, including science learning. A large body of research on the subject has over the years led to projects and policies aimed at increasing opportunities for…