How to read this series
This review is written for people who already practise or commission monitoring, evaluation and learning (MEL) and who know the standard toolkit: the OECD DAC criteria, randomised controlled trials (RCTs) as the reference design for impact evaluation, contribution analysis, participatory evaluation, Most Significant Change. It does not re-explain those.
Instead it asks what has changed around them in roughly the last ten years — which new approaches have become mainstream, which words you now need to recognise in a terms of reference or a conference programme, and which arguments remain unsettled.
Each of the twelve sections follows the same pattern: what changed, the frameworks and tools that carry the change, the vocabulary, the live controversies, and a short list of further reading that mixes expert media and blogs with peer-reviewed journals. A glossary of the decade's lingo and a list of outlets worth following close the page. Links were checked in September 2026; journal links go to the publisher's page, which may be paywalled, and open-access versions are noted where they exist.
Three cross-cutting shifts frame everything that follows. First, the centre of gravity moved from measuring toward learning and adapting: the very acronym changed from M&E to MEL (and MEAL in humanitarian agencies). Second, the methods debate broadened from "RCT or nothing" into a plural, theory-based, judgement-explicit repertoire, while RCTs themselves reached their institutional peak with the 2019 Nobel prize.
Third, questions of power — who defines value, who owns evidence, whose knowledge counts — moved from the margins of evaluation theory into donor policy, professional standards and, in 2025, a political backlash. The dismantling of USAID in 2025 then removed the single largest buyer of MEL services in the world and turned many of these debates from theoretical to existential.