This paper discusses adapting Churches' approach to large-scale teacher/researcher conceptual replications of major "science of learning" findings, to increase teachers' engagement with empirical research on, and building research networks for, gathering data on the science of learning. The project here demonstrated the feasibility of teacher-led randomised controlled trials for conceptually replicating the effects of cognitive science on learning, as specified by researchers. It also indicated high levels of interest by teachers in applying more science of learning in their practice. The approach gave freedom to teachers to design interventions, choose research methods, and measure outcomes, even though such freedom would be in tension with some scientific research which relies on constraining the sources of variation. This paper discusses how a balance can be struck between the objectives of teachers and researchers engaged in replicating cognitive science findings, and promoting teacher engagement in conceptual replication research.