Just dropping by to highlight a recent Nature article that has a clear-eyed take on the value of synthesizing evidence for policymakers. There’s a lot of discussion of “evidence-informed policy,” but it’s not as commonly noted that aggregating evidence across studies is often more useful than presenting the results of a single study.
Two interesting examples from the authors:
To help address rising childhood obesity, researchers from Australia, Hong Kong and the United Kingdom collated and systematically analysed 55 studies, together involving tens of thousands of children. The result was one of the most influential medical reviews1. It has been cited nearly 1,500 times since its publication in 2011, following nearly two years of work.
By contrast, it only took two days for the UK government to convene its Scientific Advisory Group for Emergencies (SAGE) following the 2011 disaster at the Fukushima nuclear plant in Japan, caused by an earthquake that hit the country’s east coast (see go.nature.com/2jxotw6). Experts from within and outside government, including geologists, meteorologists, radiation-health experts and behavioural scientists, rapidly modelled a range of possible scenarios. Within six days of the quake, they had advised that the risks to British nationals in Japan could be managed2…
These are both examples of evidence synthesis.
They also have a convenient graphic with best principles for synthesizing evidence.