Milestones en route to evidence-based policies.

Whilst practice may always be driven by tacit knowledge and experience, policies should be based on evidence that they do good rather than harm. Intuitions and theories are an insufficient guide to implementing the Hippocratic Oath to at least do no harm. The research literature from the US and UK is used to illustrate the rocky path towards the adoption of standards for evidence-based policies. Illustrations of plausible theories are provided … such as the benefits of high expectations or more time allocated to instruction. Such theories (more properly called hypotheses) have frequently been adopted by policy-makers without adequate tests or cost-benefit analyses. The growth of evaluation as a discipline/profession is discussed and three important influences on research are identified as computers, statistical developments (effect sizes and meta-analyses) and demands for accountability. The combined effects of these could make evidence-based policies feasible, effective and the best thing since sliced bread. [ABSTRACT FROM AUTHOR]