We announce the August 2022 release of COCI, the OpenCitations Index of Crossref open DOI-to-DOI citations, which is based on open references to works with DOIs within the Crossref dump dated August 2022. This new release extends COCI with more than 48 million additional citations, giving a total number of more than 1.36 billion DOI-to-DOI citation links.
This release includes citations from the articles published over the last four years by IEEE, whose bibliographic references were opened in June 2022.
A fundamental role in pushing the commercial publishers to open their citation data was played by Crossref’s recent announcement to change its reference distribution policy, by making all its metadata open.
You can find more information about COCI in our open-access article
Ivan Heibi, Silvio Peroni & David Shotton (2019). Software review: COCI, the OpenCitations Index of Crossref open DOI-to-DOI citations. Scientometrics, 121 (2): 1213-1228. DOI: https://doi.org/10.1007/s11192-019-03217-6
Finally, just a reminder that the bibliographic and citation data in COCI:
can be queried using the OpenCitations Indexes SPARQL endpoint;
Guest blog post by Alberto Martín-Martín, Facultad de Comunicación y Documentación, Universidad de Granada, Spain <firstname.lastname@example.org>
In this post, as a contribution to Open Access Week, Alberto Martín-Martín shares his comparative analysis of COCI and other sources of open citation data with those from subscription services, and comments on their relative coverage.
Comprehensive bibliographic metadata is essential for the development of effective understanding and analysis across all phases of the research workflow. Commercial actors have historically filled the role of infrastructure providers of bibliographic and citation data, but their choice of subscription-based business models and/or restrictive user licenses has significantly limited how users and other parties can access, build upon, and redistribute the information available on those platforms. Locking bibliographic and citation metadata behind these barriers is problematic, as it hinders innovation and is an obstacle to reproducibility.
Fortunately, the process of digital transformation that scientific communication is currently undergoing is providing us with the tools to get closer to the ideal of science as a public good. One of the most successful initiatives in this area is Crossref, arguably the single most critical piece of research metadata infrastructure currently in existence. I consider the best thing about it to be its commitment to openness. Not only is Crossref responsible for minting many of the DOIs that are assigned to academic publications, but it also publishes metadata about these publications (for over 120+ million records in their latest public data file) without imposing any access or reuse limitations.
Crossref metadata has already boosted innovation in a variety of academic-oriented tools. New discovery services such as Dimensions, The Lens, and Scilit all take advantage of Crossref metadata to keep their indexes up to date with the latest publications. The open-source reference manager Zotero is able to pull metadata associated with a given DOI from Crossref’s servers, providing an easy way to populate one’s personal reference collection that is more reliable than using Google Scholar. The Unpaywall database uses Crossref metadata (among other data sources) to keep track of which documents are Open Access, and this data is in turn used by Unsub, a service that helps libraries make more informed decisions about their journal subscriptions.
Historically, citation indexing has been a functionality available only from a few subscription-based data sources (most notably Web of Science and Scopus), or from free but largely restricted sources (e.g., Google Scholar). In recent years, however, commercial exclusivity over citation data has been waning. Digital publishing workflows make it easier for publishers to deposit the list of cited references along with the rest of the metadata when they register a new document in Crossref, and many are already doing it. Crossref’s policy is to make these lists of references publicly available by default, although publishers can elect to prevent their public release. From this, it follows that if most publishers deposited their reference lists in Crossref and consented to make them open, a comprehensive open citation index, one that is free of the restrictions present in traditional platforms, could be built.
The Initiative for Open Citations (I4OC) is an advocacy group that has been working since 2017 to achieve this precise goal, and it has already managed to convince a large number publishers (over two thousand) to open the references they deposit in CrossRef. In the first half of 2021, Elsevier, the American Chemical Society, and Wolters Kluwer joined this group, so that today all the major scholarly publishers now support I4OC and have open references at Crossref, with the exception of IEEE (the Institute of Electrical and Electronics Engineers). Thanks to the efforts of I4OC and the collaboration of publishers, 88% of the publications for which publishers have deposited references in CrossRef are now open. This has allowed organizations such as OpenCitations (one of the founding members of I4OC) to create a non-proprietary citation index using these data, namely COCI, the OpenCitations Index of Crossref open DOI-to-DOI citations. Other open citation indexes such as the NIH Open Citation Collection (NIH-OCC) and Refcat have also been recently released.
How do such open citation indexes compare to long-established indexes? In 2019, I set out with colleagues to analyze the coverage of citations contained within the most widely used academic bibliographic data sources (Web of Science, Scopus, and Google Scholar) to a selected corpus of 2,515 highly-cited English-language documents published in 2006 from 252 subject categories, and to compare this to the coverage provided by some of the more recent data sources (Microsoft Academic, Dimensions, and COCI). At that time, COCI was the smallest of the six indexes, containing only 28% of all citations. For comparison, Web of Science contained 52%, and Scopus contained 57%.
There are a number of reasons for those differences: first, at that point some of the larger commercial publishers including Elsevier, IEEE, and ACS, which routinely deposit references in Crossref, hadnot yet opened them. Second, many smaller publishers still do not deposit their reference lists in Crossref. Third, COCI only captures citation relationships between documents that have DOIs, thus missing citations to publications that lack them. Finally, while for our study data collection from all sources was carried out during May/June of 2019, COCI at that time had not been updated since November 2018, which increased its disadvantage when compared to other data sources with more frequent updates.
Since Elsevier is the largest academic publisher in the world, its recent opening of references at Crossref resulted in a significant increase in the total number of openly available Crossref references. The most recent version of COCI (dated 3 September 2021, and based on open references to works with DOIs within the Crossref dump dated August 2021) now contains both the processed references from Elsevier, and the references in the most recently published articles by ACS (the complete backfile of ACS references will appear in future versions of COCI).
Given these significant developments, how much has the picture changed? To find this out, I updated our 2019 analysis using the version of COCI released on September 3rd 2021 and the NIH-OCC dataset released in the same month. To carry out a reasonably fair comparison while reusing the data extracted in 2019 from the other sources, I employed the same corpus of target documents, and only used citations in which the citing document was published before the end of June 2019. The intention was to learn how much the coverage of open citation data has grown as a result of the subsequent opening of reference lists in Crossref that were not public in 2019, and similar efforts. The results of this new comparison are published in .
The combination of COCI’s and NIH-OCC’s September 2021 releases contained more than 1.62 million citations to our sample corpus of documents from all areas, a 91% increase over the 0.85 million citations that we were able to recover in 2019 from COCI alone. Considering the citations available in all data sources, 53% of all citations are now available from these two open sources under CC0 waivers, up from the 28% we found in 2019. This coverage now surpasses the 52% found by Web of Science, and is much closer to the 54% found by Dimensions, and the 57% covered by Scopus. The relative overlap between COCI and the other data sources has also significantly increased: in 2019 COCI found 47% of the citations available in Web of Science, whereas now open citation data sources find 87% of the WoS citations. In the case of Scopus, in 2019 COCI found 44% of the citations available in Scopus: the percentage available from open sources has now increased to 81%. The number of citations found by COCI but not present in the other data sources has also widened slightly. These data are presented graphically in Figure 1.
Fig. 1. Percentage of citations found by each database, relative to all citations (first row), and relative to the number of citations found by the other databases (subsequent rows).
Where are these new citations coming from? Well, as we might expect, references from articles published in Elsevier journals comprise the lion’s share of the newly found citations in open data sources (close to half of all new citations), as shown in Figure 2. But there are also some IEEE citations here. This is because until recently reference lists from IEEE publications were available in the ‘limited’ Crossref category to members of Crossref Metadata Plus, a paid-for service that provides a few additional advantages over the free services Crossref provides. As a member of Crossref Metadata Plus, OpenCitations obtained these reference lists while they were available and included them in COCI. Subsequently, IEEE decided to make their references completely closed, explaining why references from more recent IEEE publications are not included in COCI.
Fig 2. The increases between 2019 and 2021 of citations indexed by open sources (COCI + NIH-OCC) from the articles of different publishers
There can be no doubt that open citation data is of benefit to the entire academic community. Thanks to COCI, NIH-OCC, and similarinitiatives, and despite some setbacks, we are already witnessing how open infrastructure can help us develop models and practices that are better aligned with the opportunities that our current digital environment offers and the challenges that our society faces.
Conclusion: The coverage of citation data available under CC0 waivers from open sources is now comparable to that from subscription sources such as Web of Science and Scopus, offering a viable alternative upon which to base open and reproducible metrics of academic performance.
 Martín-Martín, A., Thelwall, M., Orduna-Malea, E. et al. Google Scholar, Microsoft Academic, Scopus, Dimensions, Web of Science, and OpenCitations’ COCI: a multidisciplinary comparison of coverage via citations. Scientometrics126, 871–906 (2021). https://doi.org/10.1007/s11192-020-03690-4
Most of the talks at this conference have focussed on open access to textual content. But open bibliographic metadata is also vitally important, not least to enable the calculation of metrics that are both open and reproducible.
OpenCitations is a not-for-profit open infrastructure that provides such free access to global scholarly citations. We hold dear the values and principles that underpin Open Science, and are early adopters of the Principles of Open Scholarly Infrastructure (POSI) and the FAIR data principles.
Our largest citation index is COCI, the OpenCitations Index of Crossref open DOI-to-DOI citations, which currently indexes approximately 1.2 billion citations, released to the public domain under a CC0 waiver.
Our goal is for OpenCitations to provide open bibliographic citation information having scope, depth, accuracy and provenance that surpasses that of the commercial citation indexes, for access to which scholarly institutions presently pay enormous annual subscriptions.
I wish to mention just two of our planned developments:
OpenCitations Meta is a new database that will enable us to store in-house full bibliographic metadata about citing and cited publications. This will have two advantages: It will speed user queries, since we will no longer have to wait for responses to on-the-fly API calls to Crossref and ORCID to retrieve such metadata. More importantly, it will enable us to index the large number of references involving publications that do not have DOIs, something that for technical reasons is presently lacking.
Additionally, we plan to develop new citation indexes over other sources of open references, starting with DOCI, indexing references from DataCite, and NOCI, indexing the content of the NIH Open Citation Collection.
Our progress has until recently been severely manpower-limited. However, OpenCitations was fortunate to have been selected by SCOSS, the Global Sustainability Coalition for Open Science Services, as an open infrastructure providing a unique and valuable service, and worthy of crowdfunded financial support by the global stakeholder community of research institutes, academic libraries, funders and publishers.
As a result of the generous support so far provided or pledged by ~50 such institutions, we have already reached about one-third of our requested SCOSS budget, enabling us this year to appoint new staff to start our planned technical developments, to support our community outreach, and to help take our vision forward.
Such financial support is vital for our sustainability, since we generate no income from our provision of free data, services and software. We thus invite you too to contribute to OpenCitations.
However, we also seek community involvement in other ways: participation in the community-led governance of OpenCitations; help in developing our open source software and services; curatorial involvement to improve OpenCitations data; and collaborations with other like-minded infrastructures to develop federated access to open scholarly information of all types, thereby returning control over such information to the academic community that generated it in the first place.
If you would like to work with OpenCitations in any of these ways, please contact me.
We are happy to announce OpenCitations’ participation in a number of online conferences and events during the next few weeks. Our directors Silvio Peroni and David Shotton will be speaking at the Open Science Fair 2021, the OASPA Conference 2021 and Open Access Tage.
Open Science Fair 2021 (20-23 September) is an event organized by OpenAIRE, in collaboration with some key international initiatives in the area of Open Science: COAR, EIFL, Force11, LA Referencia, LIBER, OPERAS, Sparc, Sparc Europe. Like a real fair, the visitors can explore virtual pavilions, participating in various Keynote Talks, Parallel Sessions and Workshops dedicated to Open Science. Silvio Peroni will give two talks on Tuesday 21:
The Workshop “The perils of being invisible. Collective funding models for Open Science infrastructure” (16:30-18:00 CEST) “will help identify the main challenges of collective funding models for Open Science Infrastructure, as well as explore the path forward to make them more efficient”. Silvio Peroni, Niels Stern (DOAB/OAPEN)James MacGregor (PKP), Agata Morka (SPARC Europe/SCOSS), Jon Treadway (the Great North Wood Consulting), Jean-Francois Lutz (University of Lorraine) and Vanessa Proudman (SPARC Europe) will reflect on the evanescence of Open Science Infrastructure (OSI) in library budget considerations. The speakers will also promote interaction with other workshop participants in order to create a collective dialogue. You can register for the event here: https://www.opensciencefair.eu/2021/workshops/the-perils-of-being-invisible
The OASPA Conference 2021 (21-23 September), entitled “Designing 21st Century Knowledge Sharing Systems”, will be dedicated to “many timely and fundamental topics relating to open scholarly communication”, including “the ongoing impact of the pandemic”. David Shotton will take part in the Poster Lightning Talks Session 3 (Thursday 23, 1-2 pm BST), with the title “OpenCitations – what does the future hold?”, a reflection on OpenCitations’ values, data, services, achievements so far, and plans for the future. For further information and registration: https://oaspa.org/conference/
Silvio Peroni, together with James MacGregor (Public Knowledge Project) and Niels Stern (OAPEN) will hold the Workshop “How Open Infrastructure Benefits Libraries?” (September 27, 11:30-13 CEST) as part of the Open Access Tage 2021 (27-29 September), an annual event dedicated to Open Access initiatives and community. During the workshop, the speakers will investigate the social and economic value of open infrastructures for libraries. For more information and to register for the event: https://oat21.sched.com/event/kdFg/workshop-2-how-open-infrastructure-benefits-libraries
We thank the organizers of these prestigious international events for having invited OpenCitations to participate. The Open Science resounds and grows through such community-centered initiatives.
If you wish to learn more about Open Science, ongoing Open Access initiatives, and OpenCitations’ commitment to and activities within these areas, don’t miss the opportunity to participate in these on-line conferences … see you there!
“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”.
Cite this article as: Chiara Di Giambattista, "Crossing a significant threshold: more than one billion citations now available in COCI!," in OpenCitations blog, 04/08/2021, https://opencitations.hypotheses.org/1253.
Here’s some information about their backgrounds, positions and roles at OpenCitations.
Claudio Fabbri (Administrator and Research Manager):
Claudio has taken responsibility for all the day-to-day administrative activities of OpenCitations, including financial arrangements with those organisations supporting OpenCitations and bureaucratic interactions involving our host institution, the University of Bologna.
“After graduating in philosophy, I worked for several years as a librarian in university libraries. Considering my professional background, it came naturally to me to get in touch first with the Open Access movement and then, in a broader view, with Open Science principles. Now, as the Research Manager for OpenCitations, I’m proud to lead the administrative work for this great infrastructure. I’m interested in the history of science, especially how scientific communication has changed over the years”.
Chiara Di Giambattista (Communications Director and Community Development Manager):
Chiara takes care of all communications and social interactions made on behalf of OpenCitations, in terms of outreach to the scholarly community, contacts with present and potential supporting organisations, and OpenCitations’ communications via social media. She is developing a comprehensive mission statement and communications strategy for OpenCitations, designed to enhance the community’s understanding of OpenCitations’ global mission and awareness of its financial needs, to increase usage of OpenCitations services, and to foster collaborative interactions with like-minded infrastructures and institutions.
“I graduated in Visual Arts at the University of Bologna with the thesis “Presenting the future in the Digital Age. The semiotic convergence between art and IxD design in the practice of Future Casting”. Being deeply passionate about the adaptive potential of language in all its forms, from classical linguistics to visual semiotics, I have various experiences in web journalism and publishing. My role in OpenCitations is to improve the engagement of OpenCitations with the scholarly community, to develop OpenCitations’ social media platforms (LinkedIn and Twitter) and the OpenCitations blog, and to communicate and promote the values, services and impact of OpenCitations throughout the world”.
Giuseppe Grieco (Software and Systems Developer):
As a skilled computer scientist, Giuseppe will take charge of all the technical development related to the OpenCitations services, data acquisition, and bibliographic metadata and citations provision.
“I have a degree in computer science. I have been passionate about this field since I was thirteen years old, when I started to learn the basics of algorithms and programming. Most recently, I have been dedicating myself to artificial intelligence by pursuing Masters studies at the University of Pisa. I have always tried to take every opportunityto put into practice what I’ve been studying . Now, with my appointment at OpenCitations, I will do so by developing upgrades and enhancements to the existing software infrastructure”.
More new people will be getting involved in OpenCitations in the autumn. Watch this space!
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.
Cite this article as: Chiara Di Giambattista, "OpenCitations at LIBER Annual Conference 2021: ‘How Can Open Infrastructures Support the Role of Research Libraries?’," in OpenCitations blog, 20/07/2021, https://opencitations.hypotheses.org/1222.
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.
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.
OpenCitations is proud to be part of the launch of the Initiative for Open Abstracts, a new cross-publisher initiative calling for the unrestricted availability of abstracts to boost the discovery of research.
The Initiative for Open Abstracts (I4OA), launched on September 24th, calls on all scholarly publishers to open their abstracts, and specifically to deposit them with Crossref, in order to facilitate large-scale access and promote discovery of critical research.
Making abstracts openly available helps scholarly publishers to maximize the visibility and reach of their journals and books. Open abstracts make it easier for scholars to discover, read and then cite these publications; promotes their inclusion in systematic reviews; expands and simplifies the use of text mining, natural language processing and artificial intelligence techniques in bibliometric analyses; and facilitates scholarship across all disciplines by those without subscription access to commercial bibliographic services.
Many abstracts are already available in various bibliographic databases, but these sources have limitations, for example because they require a subscription, are not machine-accessible, or are restricted to a specific discipline. I4OA thus calls on all scholarly publishers using Crossref DOIs to make their abstracts openly available by depositing them with Crossref. This can be done as part of established workflows that publishers already have in place for submitting publication metadata to Crossref.
As detailed on the I4OA web site at https://i4oa.org, 40 publishers have already agreed to support I4OA and to make their abstracts openly available. I4OA is also supported by 56 other stakeholders including research funders, libraries and library associations, infrastructure providers, and open science organizations, demonstrating the importance and relevance of this Initiative to the scholarly community. The launch press release is available at https://i4oa.org/press.html#pressrelease.
I4OA was inspired by the success of the Initiative for Open Citations (I4OC, https://i4oc.org/), which encourages the submission of references to Crossref. Since the launch of I4OC in 2017, over two thousand scholarly publishers have chosen to make the reference lists of their journal articles and book chapters openly available through Crossref. I4OA aims to replicate the success of I4OC by achieving a rapid jump in the open availability of scholarly abstracts via Crossref.
OpenCitations is an innovative infrastructure organization for open scholarship dedicated to the publication of open bibliographic and citation data concerning academic publications as Linked Open Data using Semantic Web technologies, thereby providing a disruptive alternative to traditional proprietary citation indexes. It also undertakes related advocacy work, particularly as a founding member of the Initiative for Open Citations (I4OC).
OpenCitations developed the OpenCitations Corpus (OCC), a database of open downloadable bibliographic and citation data recorded in RDF and released under a Creative Commons CC0 public domain waiver, which currently contains information about 14 million citation links to over 7.5 million cited resources. In addition and separately, OpenCitations is currently developing a number of Open Citation Indexes, using the data openly available in third-party bibliographic databases. The first and largest of these is COCI, the OpenCitations Index of Crossref open DOI-to-DOI citations, which presently contains information encoded in RDF on more than 445 million citations, released under a CC0 waiver.
OpenCitations structures its data according to the OpenCitations Data Model (OCDM), that may also be employed by third parties, either for their own use or to structure their data for submission to and publication by OpenCitations. This model uses OpenCitations’ suite of SPAR (Semantic Publishing and Referencing) Ontologies developed to describe all aspects of the scholarly publishing domain. OpenCitations has also published open software of generic applicability for searching, browsing and providing REST APIs over RDF triplestores.
OpenCitations fully supports the founding principles of Open Science. It complies with the FAIR data principles proposed by Force11 that data should be findable, accessible, interoperable and re-usable, and it complies with the recommendations of I4OC that citation data, in particular, should be structured, separable and open. OpenCitations has published a formal definition of an open citation, and has launched a system for globally unique and persistent identifiers (PIDs) for bibliographic citations – the Open Citation Identifiers (OCIs) – for which it maintains an OCI resolution service.
OpenCitations has the potential to be a game-changer in the scholarly information landscape, giving institutions and individuals the ability to analyse and reuse publication citations in other infrastructures, in library collections, and in research. Open citation data are particularly valuable for bibliometric analysis, increasing the reproducibility of large-scale analyses by enabling the publication of the source data upon which analytical results are based. Since citation data are also crucial to evaluating research performance, such access to open, transparent citation data sources is a priority for Open Science.
SCOSS was formed in early 2017 with the purpose of providing a new coordinated and targeted crowd-sourcing and cost-sharing framework to enable the Open Access and Open Science communities to support the open infrastructure services on which they depend. In its first funding cycle, more than 1.5 million euros was pledged by more than 200 institutions worldwide to help fund and sustain the Directory of Open Access Journals (DOAJ) and SHERPA/RoMEO.
With the launch of its second funding cycle, SCOSS is appealing to academic institutions and their libraries, research institutes, publishers, funding organisations, national and regional governments, international organisations, learned societies and service providers worldwide — everyone who is invested in Open Access and Open Science — to support one or more of these three new selected open infrastructure services through a three-year commitment.