Association for Public Policy Analysis & Management

The appeal of evidence-based practices is that they allow us systematically to derive answers to pressing public questions about the use of resources or uses of coercion to promote an end. Since the period of the Enlightenment, “evidence” provided a way to challenge systems of power, to challenge existing practices. Aligned closely with knowledge, evidence could liberate. Evidence-based practices require that interventions be justified through a systematic method designed to avert whimsy, what he have conventionally called the scientific method. The highest level of knowledge using such a method is knowledge derived from the randomized control trial, the most unambiguous mode for evidence derivation.

There are critics of EBP. It is not that they oppose the norm of justification based on defensible assertions. The question raised by many critics of EBP concerns what we mean by, or what constitutes, “evidence.” Nancy Cartwright is arguably one of the most prominent of such critics. Her attention to EBP focuses upon policy interventions and the justifications for them.

In our paper we outline Cartwright’s argument to show the epistemic critique of EBP. This is a powerful consideration of the limits of EBP, but we suggest that the critique crucially misses practice dimension, which we call the practice critique. We argue that EBP reformulates the classical concept of the politics-administration dichotomy, that politics and administration are properly independent spheres. Whereas the previous concern of this dichotomy has been to prevent politics from corrupting administration, our present concern is with how the space of politics is restricted by administrative practices. We explain the practices of EBP through a management framework that considers levels of certainty and levels of agreement concerning an issue or problem. We use it here to show the relevance of hegemony and control that we see as intrinsic to EBP. Measurement and metrics are not merely value-neutral expressions of observable realities; measurement and metrics produce policy realities.