Abstract
Policy-based monitoring programmes often fail to yield the information required to assess and improve policies and plans. A dominant cause of this problem is the ‘one-size-fits-all’ (OSFA) trap—a failure to recognise that several, complementary types of monitoring are required to support effective policy. There is a need for accessible, high-level guidance on how to avoid the OSFA trap. We synthesised the literature to define three types of policy-based monitoring: (1) state and trends monitoring; (2) implementation and compliance monitoring; and (3) monitoring to improve the effectiveness and efficiency of local interventions. We present case studies to show how the OSFA trap is resulting in freshwater policies and plans with confused monitoring requirements, jeopardising policy and plan effectiveness. We offer five pragmatic strategies to avoid the OSFA trap and build complementarity among monitoring types. First, take a structured approach to defining and prioritising fundamental monitoring objectives (the desired ‘ends’) with policy-makers. Second, triage is necessary, so to improve programme efficiency, prioritise means as well as ends. Third, embrace adaptive monitoring to ensure monitoring objectives continue to align with changing priorities. Fourth, foster cross-jurisdictional partnerships, noting agencies have common information needs but insufficient resources to meet those needs on their own. Fifth, when writing policy, policy-makers should leave room for the agencies implementing the policy to employ Strategies 1–4, such that they may design monitoring programmes that satisfy all of their information requirements.