Can cognitive research generate usable knowledge for elementary science instruction? Can issues raised by classroom practice drive the agenda of laboratory cognitive research? Answering yes to both questions, we advocate building a reciprocal interface between basic and applied research. We discuss five studies of the teaching, learning, and transfer of the "Control of Variables Strategy" in elementary school science. Beginning with investigations motivated by basic theoretical questions, we situate subsequent inquiries within authentic educational debates--contrasting hands-on manipulation of physical and virtual materials, evaluating direct instruction and discovery learning, replicating training methods in classroom, and narrowing science achievement gaps. We urge research programs to integrate basic research in "pure" laboratories with field work in "messy" classrooms. Finally, we suggest that those engaged in discussions about implications and applications of educational research focus on clearly defined instructional methods and procedures, rather than vague labels and outmoded "-isms."