The teaching-learning relationship in online microteaching was explored using mixed methods. Adults (N = 40) alternated roles of "teacher" and "student" during a 15-min language learning session. Video analysis using a context-specific framework based on the science of learning revealed diversity in teaching approaches. Multiple regression revealed teaching behaviors that had been reasoned to build and consolidate knowledge contributed to learning but behaviors that had been reasoned to engage the student appeared to have a negative impact. No relationship was found between learning and participants' teaching experience (which was chiefly teaching second languages to children). Results demonstrate the complexity of teaching and its irreducibility to a set of prescriptive behaviors. They also suggest that a process-based context-specific analysis of online microteaching can provide a "bridging" tool for researchers and practitioners to address fundamental questions about teaching and so develop a "science of teaching".