When is it justified to claim that a practice or policy is evidence-based? Reflections on evidence and preferences

There has been a widespread call to adopt evidence-based practices and policies in various fields, including healthcare, education, social work, criminal justice, business management, and environmental management.

This article discusses when it is justified for an individual or organisation to claim that a specific practice or policy is evidence-based. My argument is that this is the case if, and only if, three conditions are met. First, the individual or organisation possesses comparative evidence about the effects of the specific practice or policy in comparison to the effects of at least one alternative practice or policy. Second, the specific practice or policy is supported by this evidence according to at least one of the individual's or organisation's preferences in the given practice or policy area. Third, the individual or organisation can provide a sound account for this support by explaining the evidence and preferences that lay the foundation for the claim.

My argument has at least three noteworthy implications. First, it is possible that some, but not others, are justified in claiming a given practice or policy is evidence-based. Second, being justified in claiming that a practice or policy is evidence-based does not imply that this practice or policy ought to be implemented, not even according to the claimant. Third, the individual's or organisation's preferences ought to guide the collection of evidence to help them identify what the best practices and policies are based on their normative stance.