Our recent news item Open access increase correlated with jump in Bath citation rates has attracted lots of interest. This blog post fills in some of the details behind the story.
We analysed journal articles and review papers published by University of Bath researchers between 2010 and 2015.
We used Pure (the University’s internal research information system) and the Library’s records of APC payments to identify publications that are:
- green open access – i.e. an author’s accepted manuscript shared via the University’s repository with or without an embargo,
- gold open access – i.e. the University of Bath has paid/assigned a voucher for the final published version to be freely available from the publisher’s website.
We used SciVal to access and benchmark citation data for these publication. Publications’ DOIs acted as the bridge between our internal records and SciVal.
Our benchmark group is all University of Bath journal articles and review papers (indexed by Scopus/SciVal) rather than only ‘closed access’ papers because it’s hard to definitively identify closed access papers. For example, even if we haven’t got an open access version in our repository, the paper could still be openly available elsewhere.
We describe a paper as highly cited if it is among the top 10% most cited papers for in the world for its year of publication and subject area (assigned by Scopus/SciVal ASJC subject categories).
Here’s what we found:
|Number of articles & reviews published 2010-15||Percentage of these papers that are highly cited|
|University of Bath all papers||
|University of Bath green open access||
|University of Bath gold open access||
This shows a correlation between open access and higher citations. But of course correlation doesn’t necessarily imply causation. While we’re seeing strong up take of green open access right across the board (over 80% of recent University of Bath research articles recorded in Pure comply with HEFCE’s open access policy), the University of Bath’s use of gold open access is more selective. The gold open access papers identified above either published research funded by one of the UK’s Research Councils or they qualified for use of University of Bath’s internal open access fund. This fund is designated for publishing top quality research.
The University’s investment in gold open access growing. We paid APCs/allocated gold open access vouchers for over 150 papers in the academic year 2015/16, amounting to roughly 10% of the University’s article and review publishing for the year. So we will continue to monitor citation rates for open access papers with interest.
Katie Evans, Research Analytics Librarian