Classroom response systems (CRSs) are a promising instructional technology, but most literature on CRS use fails to distinguish between technology and pedagogy, to define and justify a pedagogical perspective, or to discriminate between pedagogies. Technology-enhanced formative assessment (TEFA) is our pedagogy for CRS-based science instruction, informed by experience and by several traditions of educational research. In TEFA, four principles enjoin the practice of question-driven instruction, dialogical discourse, formative assessment, and meta-level communication. These are enacted via the question cycle, an iterative pattern of CRS-based questioning that can serve multiple instructional needs. TEFA should improve CRS use and help teachers "bridge the gap" between educational research findings and practical, flexible classroom strategies for science instruction.