Using policy related metrics responsibly in research assessment

Important things to know if you’re planning to use metrics or indicators based on Overton’s data

Overton’s search and filtering capability makes it quick and easy to find policy documents authored by your academics or citing your institution’s research.

Often you’ll want to focus on the qualitative aspects of the data – to find potential case studies, alert researchers to interesting uses of their work or to highlight successes in particular collaborations or topics, for example.

But sometimes you need something more quantitative: to measure change, see trends over time, compare yourself to other institutions or for a policy related KPI.

You may also want to use the data to assess a grant, a group or an academic.

In these cases it’s important to understand the caveats and limitations of the data. We’ve collected some useful notes below, but would also encourage you to reach out with any questions, big or small – we’re very happy to advise if you’re unsure about whether or not the data can answer a particular question, or how to pull out the information you need. 

You can contact us directly through the app or at

What does the database represent?

  • Remember that when looking at Overton data you’re looking at policy documents that have been indexed by Overton, not all policy documents ever written. We may be missing older documents, for example, or the document might never have been made publicly available online.
  • The definition of a policy document is subjective. The one we use is quite broad: documents written primarily for or by policymakers (more here). 
  • There are always new policy sources to add and we’re still working through the list. There are some kinds of policy source that we wouldn’t automatically add: you can see our minimum criteria for inclusion here.
  • In general the data for better developed countries is more complete. Some countries are better represented than others.

Reference extraction

  • Overton currently matches references to other policy documents, scholarly works with a DOI and links to mainstream news sources.
  • Some outputs fall into both categories: for example the OECD may publish work in a journal (so it’ll appear in the scholarly works set) and also make it publicly available on their website (so it’ll appear in the policy document set). 
  • Note that many books – especially older books and monographs – have never been assigned DOIs and so references to them will not be picked up by Overton. This is something we’re actively working on.
  • Generally speaking Overton is language agnostic but we may miss references from documents in some languages depending on the style of citations they are using.
  • Reference matching is one of our core competencies and Overton’s reference matching compares very favourably to other systems, but we can’t always resolve references to a DOI and can sometimes match to an incorrect DOI, especially if there are multiple articles with very similar titles and publication dates in the same journal.

Author and institution disambiguation

  • By default we use institutional affiliation data from OpenAlex but can support other systems too with some custom work – please get in touch if this is something you’d like to explore.
  • The institution list isn’t a hierarchy: if a medical school appears as a separate institution in OpenAlex then it won’t appear in searches for the parent institution and vice versa.
  • We don’t yet disambiguate authors e..g if an author has a middle initial in the author list of one paper and not in another, they’ll appear as two different people in Overton.
Updated on February 8, 2024

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