Why is it important that Elsevier is going to open its citations?

Both DORA and the Initiative for Open Citations (I4OC) have called on publishers to make the reference lists of their articles openly available. In response to this, almost all large and medium-sized publishers have made their citations openly available in Crossref. Elsevier was one of the very few major publishers that have not yet opened their citations. With Elsevier’s decision to open its citations, hundreds of millions of citations will become openly available, closing a large gap in the openly available citation data in Crossref.

Citation-based indicators play a prominent role in research evaluations. Responsible use of these indicators requires openness of the underlying citation data, so that the indicators are fully transparent and so that anyone can question the indicators and can even construct alternative ones. Elsevier’s decision to open its citations therefore represents a significant step toward more responsible use of citation-based indicators in research evaluations.

Citation data is also highly valuable to support the discovery of scientific literature. Elsevier’s decision to open its citations can be expected to stimulate the development of innovative new discovery tools. Elsevier itself will also benefit from this, since the articles it publishes will be easier to find and as a result will attract more readers.

Why has it taken so long for Elsevier to open its citations?

The most important reason seems to be that Elsevier considered open citations to be a threat to its Scopus business. By keeping its citations closed, Elsevier used its strong position as a publisher to protect its Scopus business. The increasing pressure on Elsevier to support initiatives focused on promoting responsible research assessment (e.g., DORA) and open science (e.g., I4OC) has led to a change in its policy. While opening citations may indeed result in more competition for Scopus, it may also help Elsevier to shift its focus from monetizing data to providing value-added services, which in the longer term may be expected to be commercially more attractive.

Have all citations now been opened?

In January 2021, when Elsevier’s citations will be opened, the percentage of citations in Crossref that are open will increase from 60% to probably more than 90%. With Elsevier opening its citations, almost all large and medium-sized publishers that work with Crossref will have opened their citations. However, there are still a few exceptions. The largest one is IEEE, followed by the American Chemical Society (ACS) and the University of Chicago Press. Hopefully these publishers will now also change their policy and open their citations.

What is the significance of Elsevier’s decision to open its citations in Crossref, given that Microsoft Academic already makes Elsevier citations openly available?

By making large amounts of bibliographic metadata openly available, Microsoft Academic provides a great service to the scientific community. A platform such as the Lens, which relies strongly on data from Microsoft Academic, shows the value of this data. However, open availability of citations and other bibliographic metadata in Crossref has at least two additional advantages. First, Crossref has made a commitment to follow the Principles of Open Scholarly Infrastructure, which helps to ensure the long-term sustainability of its activities. Second, Microsoft Academic makes data available under an ODC-BY license, which requires Microsoft Academic to be acknowledged when the data is used. In contrast, Crossref considers the data it makes available to be facts and does not attach a license to it. Compared with data from Microsoft Academic, data from Crossref is therefore easier to reuse and easier to combine with data from other sources.

How does Elsevier’s decision to open its citations affect commercial platforms such as Web of Science, Scopus, and Dimensions?

The core data provided by these commercial platforms will increasingly also be openly available, making it more challenging for these platforms to monetize their data. However, at the moment these platforms still provide a significant amount of data that cannot easily be obtained from an open data source such as Crossref. Web of Science and Scopus for instance make data available for journals that do not work with Crossref. They also provide enriched data, for instance by disambiguating authors and institutions. In the longer term, the business models of Web of Science and Scopus can be expected to shift from providing data to offering value-added services on top of the data. There is still a lot of room for innovation in this area.

The situation for Dimensions is similar, with one important difference. Dimensions combines Crossref data with data obtained from publishers. While the increasing open availability of data in Crossref may decrease the value of the data provided by Dimensions, it will also reduce Dimensions’ dependence on publishers, which may make it easier for Dimensions to maintain and expand its platform.

What about open abstracts?

By opening its citations, Elsevier supports the Initiative for Open Citations (I4OC). It does not yet support the Initiative for Open Abstracts (I4OA), which was launched earlier this year and which calls on publishers to make abstracts openly available in Crossref. Many publishers have already joined I4OA, including AAAS, BMJ, Cambridge University Press, F1000, Frontiers, Hindawi, MDPI, Oxford University Press, PLOS, PNAS, Royal Society, and SAGE. Elsevier still needs to take this step. Like citation data, abstracts play an important role in research evaluations, for instance to delineate the literature on specific research topics or in specific research areas (e.g., the sustainable development goals). A full commitment to promoting responsible research assessment therefore requires not just openness of citations but also of abstracts and other bibliographic metadata.

Ludo Waltman is one of the founders of the Initiative for Open Abstracts (I4OA). In 2019 he resigned as Editor-in-Chief of Elsevier’s Journal of Informetrics, protesting against Elsevier’s unwillingness to open its citations.