"What counts as good evidence?" is a great conversation starter. The UK-based Alliance for Useful Evidence / Nesta hosted a London seminar to "explore what is realistic in terms of standards of evidence for social policy, programmes and practice." Details: What is Good Evidence? Standards, Kitemarks, and Forms of Evidence. The event was chaired by Geoff Mulgan, CEO of Nesta ; speakers include Dr. Gillian Leng, Deputy Chief Executive for Health and Social Care, NICE; and Dr. Louise Morpeth, Co-Director Dartington Social Research Unit.
Prompting that discussion was a 'provocation paper', What Counts as Good Evidence?, by Sandra Nutley, Alison Powell, and Huw Davies. They're with the University of St Andrews Research Unit for Research Utilisation (RURU).
The evidence journey. This paper is a useful recap of the state of evidence-seeking from a policy / program standpoint. While the authors do touch on bottom-up evidence schemes, the focus here isn't on crowdsourced evidence. There's a useful description of the effort to establish a basis for public policy as the evidence journey. Some highlights:
Hierarchies are too simple. We know the simple Level I/II labeling schemes, identifying how evidence is collected, are useful but insufficient. The authors explain that "study design has long been used as a key marker for evidence quality, but such ‘hierarchies of evidence’ raise many issues and have remained contested. Extending the hierarchies so that they also consider the quality of study conduct or the use of underpinning theory have… exposed new fault-lines of debate…. [S]everal agencies and authors have developed more complex matrix approaches for identifying evidence quality in ways that are more closely linked to the wider range of policy or practice questions being addressed."
Research evidence is good stuff. But the authors remind us "there are other ways of knowing things. One schema (Brechin & Siddell, 2000) highlights three different ways of knowing": empirical, theoretical, and experiential.
Do standards help? The authors provide a very nice list of evidence standards & rating schemes (GRADE, Top Tier Evidence, etc.) – that is reason enough to get your hands on a copy of the paper. And they note the scarcity of evidence on effectiveness of these rating schemes.
Davies and Nutley contributed to the excellent 2000 book What Works? Evidence-Based Policy and Practice (Davies, Nutley and Smith, Policy Press).