“The competitive benefits of closing access to citation data diminish with each new citation released to the public domain, but the benefits of open data remain. Going forward, citation data is almost completely public domain”.
With these words, from the article “A tipping point for open citationsdata” (July 15, 2021), Ian Hutchins celebrated the threshold crossing of one billion citations on public-domain databases in February 2021.
Now, a new significant milestone has been reached. We are enthusiastic to announce that COCI, the OpenCitations Index of Crossref open DOI-to-DOI citations has just been extended with 334 million additional citations. Its most recent release, the COCI July 2021 release, now contains a total of 1.09 billion DOI-to-DOI citation links derived from open references within Crossref,which includes the references of articles deposited or opened in Crossref between November 2020 and January 2021.
These numbers make us proud, and confirm the essential value of the Initiative for Open Citations (I4OC). Since 2018, the mission of I4OC has been to persuade publishers to provide open citation data by means of the Crossref platform. The I4OC untiring commitment has led the major academic publishers to a progressive change of heart regarding open citations, and the scholarly community to a deeper interest in this openness.
These factors contributed to the creation of COCI in 2018, the first open citation index created by OpenCitations, in which we applied the concept of citations as first-class data entities (Heibi I., Peroni S., Shotton D., 2019). Over the last three years, COCI has been extended in a series of releases, by harvesting citations mostly from Crossref data dumps, starting from an initial coverage of 300 million citations (First release).
A crucial event that preceded (and delayed!) this latest COCI release was Elsevier’s endorsement in the DORA Declaration on Research Assessment in December 2020, thereby making “reference lists for all articles published in Elsevier journals openly available via Crossref so they can be available for reuse. This means other important initiatives like I4OC can draw on this metadata”. As described in our previous post, Elsevier’s welcome commitment led to the opening of many previously closed references from its numerous academic journals submitted to Crossref. Now, after an extended period of data ingestion and processing, all these newly opened Elsevier references are available at OpenCitations within COCI.
Elsevier’s involvement has both an effective and a symbolical value. Even if publishing more than one billion citations is a thrilling achievement, and – as Hutchins wrote – we are now at a tipping point with regard to open citations data, this milestone is not the last stop. Together with the other organizations and projects that participate in the Initiative for Open Citations, we will keep claiming the urgency for the remaining academic publishers to join our cause, and sharing our values with the whole academic community to make all existing citations data freely open and accessible. Recalling what Dario Taraborelli wrote in the conclusion of his article “The citation graph is one of humankind’s most important intellectual achievements“, “the world is waiting for the citation graph to become a public good”.
The interconnection between Wikipedia and Wikidata is now larger than ever.
The Wikipedia Citations dataset currently includes around 30M citations from Wikipedia pages to a variety of sources – of which 4M are to scientific publication. The increase of the connection with external data services and the provision of structured data to one of the key elements of Wikipedia articles has two significant benefits: first of all, a better discoverability of relevant encyclopedic articles related to scholarly studies; furthermore, the enacting of Wikipedia as a social authority and policy hub which would enable policymakers to assess the importance of an article, person, research group and institution by looking at how many Wikipedia articles cite them.
These are the motivations behind the “Wikipedia Citations in Wikidata” project, supported by a grant from the WikiCite Initiative. From January 2021 until the end of April, the team of Silvio Peroni (director of OpenCitations), Giovanni Colavizza, Marilena Daquino, Gabriele Pisciotta and Simone Persiani from the University of Bologna (Department of Classical Philology and Italian Studies) has been working in developing a codebase to enrich Wikidata with citations to scholarly publications that are currently referenced in English Wikipedia. This codebase consists of four software modules in Python and integrates new components (a classifier to distinguish citations by cited source and a look-up module to equip citations with identifiers from Crossref or other APIs). In so doing, Wikipedia Citations extends upon prior work which only focused on citations already equipped with identifiers.
In the first two steps of the workflow (extractor and converter) the mapping between the various ways Wikipedia citations are represented in Wikipedia articles and the OpenCitations Data Model (OCDM) has been implemented and then enriched with a component responsible to find new identifiers to the entities in a dataset compliant with OCDM (enricher), while in the pusher step the mapping between the OCDM and Wikidata has been enabled, and the code has been finally released in GitHub.
WCW Workflow Diagram
The extensive documentation that has accompanied the release of the codebase is crucial for one of the principal aims of the project, I.e., the adoption and reuse of the codebase by the community in other relevant Wikimedia projects, while the engagement of various communities (Wikidata, libraries, scholars…) is favored on one side by offering an increased number of citations data included in Wikidata, on the other side by blogging and sharing the updates on Twitter and public mailing lists
This project, whose ambitious purpose is to make Wikipedia contents better discoverable and enrich Wikidata with a ready-to-use corpus for further analysis or for developing new services, is opened to future perspectives. The intention is to use the software to create a dataset of Wikipedia English citations to understand, in particular, how many new entities (i.e., citing Wikipedia pages, cited articles and venues, authors) should be added to Wikidata in order to upload all the set of extracted citations, with the result of adding a massive amount of new bibliographic-related entities to the dataset.
The first steps have been taken, now we aim to extend the engagement of the community involved, especially those scholars that leverage Wikidata in existing services, and to interact with the scholars, libraries and institutions interested in a new approach to research, focused on people (from individuals to research groups) and their intellectual relevance.
For the second year, OpenCitations has taken part in the LIBER annual conference. LIBER (Ligue des Bibliothèques Européennes de Recherche – Association of European Research Libraries) is a network that gathers 440 research libraries, based in more than 40 countries all over the world, with the mission of supporting Europe’s research libraries by highlighting their value to policymakers, providing resources and training, and forming valuable partnerships.
Since 1951, the LIBER Annual Conference is a key event for the entire network, a keenly anticipated meeting for research library professionals whose mission is “to identify the most pressing needs for research libraries, and to share information and ideas for addressing those needs”. Due to the ongoing pandemic restrictions, the 50th LIBER meeting (23-25 June 2021) was held online, as was the 2020 meeting, with digital co-hosting by the University of Belgrade Library in Serbia. The online-showcase format, however, didn’t constrain the creation of a vital virtual square, fostered by the voices of 70 speakers. The main theme of the conference, “Libraries and Open Knowledge: from vision to implementation” was deepened in 12 parallel sessions.
Professor Silvio Peroni, Director of OpenCitations, participated in Session #5 ‘How Can Open Infrastructures Support the Role of Research Libraries?’ with a presentation dedicated to the benefits of Open Infrastructures for libraries, dialoguing with James MacGregor (interim Managing Director of the Public Knowledge Project), Joanna Ball (Head of Roskilde University Library), and Niels Stern (director of OAPEN and co-Director of DOAB).
The session, chaired by Maaike Napolitano (National Library of the Netherlands) opened with a presentation by Fidan Limani (Research assistant at ZBW– Leibniz Information Centre for Economics) about the integration of scholarly artifacts from the domain of economics using Knowledge Graphs (KG), and the creation of a network of entities describing objects of interest and connections, while keeping a library perspective. The use of citation links connecting datasets and citations, and the adoption of ontologies and data exportation in RDF would facilitate a possible beneficial collaboration between ZBW and Open Infrastructures such as OpenCitations (whose data is itself in the form of a Knowledge Graph).
OpenCitations also shares some common features with the other Open Infrastructures described in the second presentation: the financial support from SCOSS project; the community-based approach; and their promising value for libraries and the entire scholarly community.
OpenCitations is an independent not-for-profit infrastructure organization dedicated to open scholarship and the publication of open bibliographic and citation data by the use of Semantic Web (Linked Open Data) technologies, engaged in advocacy for open citations and open bibliographic metadata, as a founding member of both the Initiative for Open Citations (I4OC) and the Initiative for Open Abstracts (I4OA). It provides data containing more than 7 hundred million citations that the community can use for any purpose. Such data can be crucial as a vehicle for use in national and international research evaluation exercises to make such activities more transparent and reproducible as compared to other proprietary services. Librarians can use OC citation data (e.g., via our REST API) to enhance or develop tools to support their authors, researchers, students, institutional administrators in different kind of contests, for instance by providing metrics to monitor research at your institution and by improving the discoverability of research products such as publications and data.
OAPEN is a no-profit foundation dedicated to increase the discoverability of open access books and trust around them. They are running three Open-Source platforms enabling open access to books: the Directory of Open Access Books (DOAB) – a freely available basic indexing service easy integrable within library catalogues; OAPEN Library – a publication platform dedicated to hosting, preserving and distributing books; OAPEN OA Books Toolkit – public information resource for authors to build trust around open-access books.
PKP (Public Knowledge Project) is a software and library project, consisting of three applications (Open Journal System, Open Pre-printer System and Open Monograph Press).
The dialogue during this LIBER session wasn’t a mere presentation of these projects and their technical properties: the speakers emphasized the importance of ensuring the participation and the engagement of the stakeholder community, pointed out the crucial value of the support received – not only financial – from Research Libraries, and discussed how such Open Infrastructures can be beneficial for libraries.
How can libraries support Open Infrastructures? And what role do they play in a long-term solution? According to Joanna Ball, from a librarian perspective, it’s not only a who-benefits-whom problem, but it’s more about finding a “third way, about developing mutually beneficial partnerships, and going beyond the traditional way of approaching things so that we can really play to each other’s strengths.”
This approach is fully aligned with OpenCitations’ intentions. As Silvio Peroni underlined, in most of cases the active collaboration between Open Infrastructures and libraries is not only about the financial support, but in cooperatively reach a common goal. In particular, “if infrastructures like OpenCitations provide appropriate and easy-to-use interfaces and tools that allow librarians to contribute appropriate bibliographic metadata, and if librarians are willing to enter such metadata from their own records, libraries may become a significant reliable source of this kind of information”. The result of such a ‘crowd-sourced’ entry of bibliographic metadata by libraries would be an enrichment of the overall global open knowledge graph made available through citational links.
In the last presentation, dedicated to two services provided by OPERAS, Emilie Blotière, (CNRS) and Tiziana Lombardo (Net7) reiterated the value of scholarly communication. COESO and GO TRIPLE, funded by the European Commission, aim in fact to create a persistent dialogue in the Social Sciences and Humanities community, by tackling the fragmentation and becoming a meeting point among different communities.
What emerged from the session is the importance of communication, cooperation and networking between Open Infrastructures and Libraries, and this is a message that perfectly matches with the core values of LIBER, collaboration and inclusivity. The next LIBER annual conference is scheduled for June 2022 in Odense, hopefully recreating the physical and enthusiastic gathering of the previous meetings.
At the end of 2019, OpenCitations was selected by The Global Sustainability Coalition for Open Science Service (SCOSS) for presentation to the international scholarly community for crowd-sourced sustainability funding, along with the Public Knowledge Project (PKP) and the Directory of Open Access Books (DOAB). Since 2017, SCOSS has been helping identify non-commercial services essential to Open Science, and making recommendations that these services should be considered for funding support by the global OA/OS community of stakeholders (academic institutions and their libraries, research institutes, publishers, funding organisations, national and regional governments, international organisations, learned societies and service providers worldwide, and everyone who is invested in Open Access and Open Science).
Since OpenCitations is not-for-profit and all our data and services are free, the relationship with SCOSS is crucial in maintaining and developing OpenCitations’ infrastructure and continuing to make our data and service freely available.
Thanks to the renewed engagement and support from the OA/OS Community, 2020hasbeenayearofgreatachievementsforOpenCitations.
As first described here, the starting point has been the set-up of an initial open governance structure. For administrative convenience, OpenCitations is managed by the Research Centre for Open Scholarly Metadata at the University of Bologna. Currently, the organizational bodies included in the OpenCitations governance are three: the Directors, the International Advisory Board, and the Council. All these bodies are regulated and described in two documents, “Organizational Bodies and Finances”, and “Rules for Membership” that specifically describes the criteria for Membership of OpenCitations.
The generous support received from OpenCitations’ donors and members during 2020 is making it possible to pay for necessary services and the salaries of personnel to support the daily activities of OpenCitations, thus enhancing the administration of OpenCitations and communication with new supporters and collaborators.
Separately, the involvement of OpenCitations in different funding applications throughout 2020 has led to the successful development of two projects.
The first one, OpenAIRE Nexus, started on 1 January 2021 with the aim to create a framework of services for assisting in publishing research, monitoring its impact, helping promote its discovery, and integrating it into the European Open Science Cloud (EOSC) for the benefit of the open science community worldwide. OpenCitations’ role in this will be to provide open bibliographic citations as part of the open data components of OpenAIRE and the EOSC.
The second project, the Open Biomedical Citations in Context Corpus, funded by the Wellcome Trust from July 2019 to December 2020, had the aim to expand the types of citation data provided by OpenCitations to include information about each individual in-text reference and its semantic context. This makes it possible, for example, to distinguish references that are cited only once from those that are cited multiple times, to see which references are cited together (e.g. in the same sentence), to determine in which section of the article references are cited (e.g. Introduction, Methods), and to specify the textual context of each citation, thus potentially making it possible to determine the function of the citation. Part of the grant received for this project was used to cover the salaries and expenses of developers who worked on the creation of a new persistent identifier (PID) for in-text reference pointers, the In-Text Reference Pointer Identifier (InTRePID) first described here, in the release of the new version of the OpenCitations Data Model(OCDM), and the creation of a new database, the Open Biomedical Citations in Context Corpus (CCC) containing the metadata describing the in-text references that we processed, drawn from the open biomedical literature.
Through its projects, OpenCitations has strengthened its connections with data of topical urgency. A relevant and timely output, for instance, was the creation of the Coronavirus Open Citations Dataset, which contains (as of 16 May 2020) information about 189,697 citations and about the 49,719 citing or cited articles involved in these citations related to the COVID-19 pandemic.
The involvement of OpenCitations in the SCOSS community has included our participation to several SCOSS-related events (amongst others, the SCOSS Webinar for the Couperin Consortium, the JROST Conference 2020), and the Jisc Webinar Sustaining the future of key open research infrastructure services (SCOSS) in order to present OpenCitations to the OA/OS community, together with the other Open Infrastructures selected in the first and second funding cycles. In addition, during 2020 OpenCitations participated in several international conferences, talks and meetups, including PIDapalooza 2020 and the International Semantic Web Conference 2020, and organized and co-hosted the Workshop on Open Citations and Scholarly Metadata 2020 (September 2020), gathering scholars, policy makers, publishers, and open scholarly data advocates.
Being part of the SCOSS network during 2020 has been an enriching and stimulating opportunity. The support of the international coalition for Open Science has resulted in a massive interest from European governments and Institutions (including the French Government through its National Plan for Open Science, the AgroParisTech, the Katholieke Universiteit Leuven and the Royal Danish Library), and the involvement of the Canadian Research Knowledge Network and the Council of Australian University Librarians. So far, 2021 seems to be equally promising, as judged by the increasing support being shown by US consortia for open infrastructures. Between May 2020 and April 2021 the US was responsible for 19% of the traffic to OpenCitations services, and every month has been listed in the top 4 countries using our data.
Despite the enthusiastic results, there’s still much to be done: 2020 was the first year of a three-year-long collaborative journey, in which OpenCitations will be moving forward with SCOSS to create an open, secured and inclusive future for science and research.