In a review of the challenges to progress in providing social research evidence that might usefully inform policy, Oakley (2004) argues strongly that the "paradigm divide" between qualitative and quantitative research communities continues to constitute a major problem. Oakley refers to a number of recent critiques of what is seen as "misplaced positivism" in educational research and Hammersley (1997, 2005) has suggested that educational research findings are now routinely being applied uncritically to inform educational policy and practice. Research in early childhood education has not been immune to these general criticisms and specific concerns have also been expressed regarding alleged technicism, and the reification of dominant conceptions of early educational quality. In this paper we test these theoretical claims against the realities of conducting one recent and influential early years study: the Effective Provision of Preschool Education (EPPE) Project. The paper provides an account of the EPPE research and also locates the study in terms of the contemporary literature on mixed-method research. It is argued that similar mixed-method approaches may be applied to escape many of the problems identified by critics. We conclude with a discussion of the wider implications for educational research.