The citation graph is one of humankind’s most important intellectual achievements

Dario Taraborelli at BoingBoing: “When researchers write, we don’t just describe new findings — we place them in context by citing the work of others. Citations trace the lineage of ideas, connecting disparate lines of scholarship into a cohesive body of knowledge, and forming the basis of how we know what we know.

Today, citations are also a primary source of data. Funders and evaluation bodies use them to appraise scientific impact and decide which ideas are worth funding to support scientific progress. Because of this, data that forms the citation graph should belong to the public. The Initiative for Open Citations was created to achieve this goal.

Back in the 1950s, reference works like Shepard’s Citations provided lawyers with tools to reconstruct which relevant cases to cite in the context of a court trial. No such a tool existed at the time for identifying citations in scientific publications. Eugene Garfield — the pioneer of modern citation analysis and citation indexing — described the idea of extending this approach to science and engineering as his Eureka moment. Garfield’s first experimental Genetics Citation Index, compiled by the newly-formed Institute for Scientific Information (ISI) in 1961, offered a glimpse into what a full citation index could mean for science at large. It was distributed, for free, to 1,000 libraries and scientists in the United States.

Fast forward to the end of the 20th century. the Web of Science citation index — maintained by Thomson Reuters, who acquired ISI in 1992 — has become the canonical source for scientists, librarians, and funders to search scholarly citations, and for the field of scientometrics, to study the structure and evolution of scientific knowledge. ISI could have turned into a publicly funded initiative, but it started instead as a for-profit effort. In 2016, Thomson Reuters sold its Intellectual Property & Science business to a private-equity fund for $3.55 billion. Its citation index is now owned by Clarivate Analytics.

Raw citation data being non-copyrightable, it’s ironic that the vision of building a comprehensive index of scientific literature has turned into a billion-dollar business, with academic institutions paying cripplingly expensive annual subscriptions for access and the public locked out.

Enter the Initiative for Open Citations.

In 2016, a small group founded the Initiative for Open Citations (I4OC) as a voluntary effort to work with scholarly publishers — who routinely publish this data — to persuade them to release it in the open and promote its unrestricted availability. Before the launch of the I4OC, only 1% of indexed scholarly publications with references were making citation data available in the public domain. When the I4OC was officially announced in 2017, we were able to report that this number had shifted from 1% to 40%. In the main, this was thanks to the swift action of a small number of large academic publishers.

In April 2018, we are celebrating the first anniversary of the initiative. Since the launch, the fraction of indexed scientific articles with open citation data (as measured by Crossref) has surpassed 50% and the number of participating publishers has risen to 490Over half a billion references are now openly available to the public without any copyright restriction. Of the top-20 biggest publishers with citation data, all but 5 — Elsevier, IEEE, Wolters Kluwer Health, IOP Publishing, ACS — now make this data open via Crossref and its APIs. Over 50 organisations — including science funders, platforms and technology organizations, libraries, research and advocacy institutions — have joined us in this journey to help advocate and promote the reuse of open citations….(More)”.