If you are a leader of a Library or a Research Institution and would like to learn more about the existing open infrastructures that could help your institution to evolve in the research environment, but you don’t know where to look for, you can now use Infra Finder, a brand-new tool aimed at foster discovery, adoption, and investment for open infrastructure services. Infra Finder is launched by Invest in Open Infrastructure (IOI), and is designed to be the go-to resource for anyone navigating the complex landscape of infrastructure services and standards enabling open research and scholarship.
The tool stems from the feedback collected from the community after the launch, in 2022, of the Catalog of Open Infrastructure Services pilot project in 2022, from which IOI decided to re-envision what outcomes they could affect and rethink what solutions could look like, also by furthering the Open Science principles conveyed by UNESCO’s Recommendation on Open Science, the Principles of Open Scholarly Infrastructure, and other Open Science initiatives and guidelines.
We are happy to announce that OpenCitations is among the 56 infrastructures which have accepted IOI’s invitation to be included in this first release of Infra Finder. During its development, IOI team has been constantly collecting feedback from the infrastructures involved, and has conducted user testing to understand how different people might approach it. In OpenCitations we believe that Infra Finder could serve as an helpful tool to make OpenCitations and the other infrastructure services more visible to a wider and diverse community. Infra Finder allows users to easily find and compare the catalogued services, and its intuitive use could work as a starting point towards the creation of a greater awareness of existing open infrastructures, thus leading users to further explore their features and services and, hopefully, to consider the possibility of support their sustainability.
IOI is currently planning to include new services in Infra Finder: if you are part of an organization that would like to be included, you can apply by filling out their Expression of Interest form. IOI will give two identical webinars to share with the community more details about the background and features of Infra Finder and on how interested infrastructure services can express interest in being listed. Register here to the either slot:
Research Information can be defined as an information (sometimes referred to as metadata) relating to the conduct and communication of research. This includes, but is not limited to, (1) bibliographic metadata such as titles, abstracts, references, author data, affiliation data, and data on publication venues, (2) metadata on research software, research data, samples, and instruments, (3) information on funding and grants, and (4) information on organizations and research contributors. Research information is located in systems such as bibliographic databases, software archives, data repositories, and current research information systems.
Decision-making in science is often biased by the typology of research information, and too often is based on closed research information, which is locked inside proprietary infrastructures and run by for-profit providers that impose severe restrictions on the use and reuse of the information. As a consequence, errors, gaps, and biases in closed research information are difficult to expose and even more difficult to fix. Indicators and analytics derived from this information lack transparency and reproducibility. Decisions about the careers of researchers, the future of research organizations, and ultimately the way science serves the whole of humanity, depend on these black-box indicators and analytics.
There is an urgency for a fundamental change in the research information landscape towards openness. Indeed, open research information enables science policy decisions to be made based on transparent evidence and inclusive data and information used in research evaluations to be accessible and auditable by those being assessed. It makes it possible for the global movement towards open science to be supported by information that is fully open and transparent.
Today, over 40 organizations, including the University of Bologna, are committing to making openness of research information the norm and to lead this change in the research information landscape. The signatories of the Barcelona Declaration on Open Research Information commit to taking a lead in transforming the way research information is used and produced, to make the openness of information about the conduct and communication of research the new norm.
The full text of the Barcelona Declaration is now publicly shared onbarcelona-declaration.org and presents the commitments that all the signatories of the Declaration adhere to, namely
To make openness the default for the research information we use and produce;
To work with services and systems that support and enable open research information;
To support the sustainability of infrastructures for open research information;
To support collective action to accelerate the transition to openness of research information.
In addition to the signatories, the Declaration has been supported by several organizations providing data, services and infrastructures. OpenCitations has declared its support to the Declaration, together with AmeliCA, Crossref, Curtin Open Knowledge Initiative (COKI), DataCite, EuropePMC, DOAB, DOAJ, Europe PMC, Liberate Science GmbH, OAPEN,OpenAIRE,OurResearch,Redalyc and ROR. OpenCitations believes in the Declaration as a starting point for a substantial change by promoting values which OpenCitations fully supports, as stated in the words of our Director and Associate Professor at the University of Bologna Silvio Peroni:
Since its creation in 2010, OpenCitations has always advocated and actively worked to produce open research information and develop infrastructural technologies to maximise its sharing and reuse in different applicative contexts. Thus, we embrace the Declaration’s goals and commitments and look forward to working with all the signatories to foster the use and production of open research information.
Prof. Silvio Peroni has been a part of the initial team of over 25 research information experts, representing organizations that carry out, fund, and evaluate research, as well as organizations that provide research information infrastructures, which first prepared The Barcelona Declaration on Open Research Information. The group met in Barcelona in November 2023 in a workshop hosted by SIRIS Foundation. The preparation of the Declaration was coordinated by Bianca Kramer (Sesame Open Science), Cameron Neylon (Curtin Open Knowledge Initiative, Curtin University), and Ludo Waltman (Centre for Science and Technology Studies, Leiden University).
As of April 15, 2024, the list of signatories involves universities and other research performing organizations such as Αthena Research Center (Greece), Charles University (Czech Republic), Coimbra Group (international), Hamburg University of Technology (Germany), I-CERCA – Centres de Recerca de Catalunya (Spain), Instituto Brasileiro de Informaçãoem Ciência e Tecnologia – Ibict (Brazil), Leiden University (Netherlands), Museo Galileo. Istituto e Museo di Storia dellaScienza (Italy), Otto-Friedrich-Universität Bamberg (Germany), Sorbonne Université (France), Spanish National Research Council – CSIC (Spain), Udice – French Research Universities (France), UnilLaSalle (France), Universidad de Antioquia (Colombia), Università di Bologna (Italy), Universitat de Barcelona (Spain), Universitat Politècnica de Catalunya (Spain), Université Grenoble Alpes (France), Université Le Havre Normandie (France), Université Paris Saclay (France), University of Coimbra (Portugal), University of Groningen (Netherlands), University of Maribor (Slovenia), University of Milan (Italy), University of Poitiers (France), University of the Azores (Portugal), University of the Balearic Islands (Spain), University of Turku (Finland), Vrije Universiteit Amsterdam (Netherlands); research funding organizations and governments, including Bill & Melinda Gates Foundation (US), Catalan Foundation for Research and Innovation – FCRI (Spain), Dutch Research Council NWO (Netherlands), French Open Science Committee (France), FrenchNational Research Agency – ANR (France), Fundació Internacional Josep Carreras (Spain), Région Normandie (France), Regione Toscana (Italy), ZonMw (Netherlands); other organizations: Consorci de ServeisUniversitaris de Catalunya – CSUC (Spain); EOSC Association (international), Latin American Council of Social Sciences – CLACSO (international), National Open Research Analytics, Technical University of Denmark (Denmark), State Scientific and Technical Library of Ukraine (Ukraine), TIB – Leibniz Information Centre for Science and Technology and University Library (Germany), UK Reproducibility Network – UKRN (UK).
There is a need for global and concrete action to reach the tipping point in the transition from closed to open research information, and the Barcelona Declaration on Open Research Information is open for signature by all organizations that carry out, fund, and evaluate research to support this transition.
If you want to learn more about the Barcelona Declaration, join us in the launch webinar on April 23, 1.00-2.30pm CEST. Click here to register for the webinar.
You can also keep yourself up to date by following the Barcelona Declaration’s social media channels:
Blog post by Ivan Heibi (University of Bologna), Arianna Moretti (University of Bologna) and Chiara Di Giambattista (University of Bologna).
In the past five years, the OpenCitations data has been enriched with numerous new indexes of open citation data from different sources. However, the quantity and diversification of the ingested information have raised several issues, which recently made it essential to conduct a complete revision of the ingestion workflow. The result was a revolution in the way OpenCitations data is delivered. In this blog post, we will explain the context and challenges raised by the old procedure. Then, we will present the new ingestion workflow, designed to produce just two comprehensive collections: OpenCitations Index, collecting open citation data, and OpenCitations Meta, for the open bibliographical metadata.
Once upon a time, there were five OpenCitations indexes…
In 2018, OpenCitations released the kickoff version of its first citation index, COCI (citations from Crossref), which contained around 300 million citation links derived from the subset of the reference lists in the Crossref database, where citing and cited entities were identified using Digital Object Identifiers (DOIs). COCI gathered citations with associated metadata in compliance with the recommendations from the Initiative for Open Citations (I4OC) that citation data should be structured, separable, and open, thus marking a turning point by providing a disruptive and free and open alternative to earlier sources such as Google Scholar, which provided freely accessible data although not downloadable, and Web of Science or Scopus, which demanded paid access.
In a short time, COCI became a competitive and trusted index of citation data, used by numerous institutional repositories, including B!son and Optimeta. In 2021, COCI was taken into account in a comparative study with the most relevant sources in the landscape, including the proprietary ones, which showed its coverage approaching parity with those of the other sources involved in the analysis (Microsoft Academic, Scopus, Dimensions, and Web of Science). At the time of its most recent update in January 2023, COCI counted more than 1.4 billion citations. The reason behind this outstanding number lies in several factors, including Elsevier’s endorsement of the Declaration on Research Assessment (DORA) in December 2020, leading to the open release via Crossref of the reference lists of the articles published in all its journals, and confirming the value of initiatives such as the Initiative for Open Citations (I4OC).
However, before this change of heart, in 2019 OpenCitations had tried to narrow the open citations coverage gap by launching its second index, the Crowdsourced Open Citations Index (CROCI). This index allowed publishers and scholars to contribute directly by uploading crowdsourced open citations into the OpenCitations infrastructure.
In December 2022, a new concrete step towards a factual plurality of OpenCitations indexes was taken by the ingestion of new data sources into the infrastructure, with the publication of the inaugural dumps of DOCI (citations from DataCite) and POCI (citations from PubMed). In June 2023, the first version of the OROCI (citations from OpenAIRE) dump was released too, and JOCI (citations from JALC) is expected to be available by the end of November 2023, for a total of five collections from different sources.
Why a new workflow? The issues with multiple sources management and new challenges
While having such a variety and richness of indexes helped present the extent of OpenCitations sources, the recent increment in the number of sources and the diversification of data integrated led to two primary issues:
the necessity to handle the ingestion of new identifier types in a DOI-based software infrastructure, and
the consequent possibility of encountering the same citation expressed by several sources with different identifiers.
Moreover, it soon became evident the need to optimize the reuse of the already developed software components to facilitate the metadata crosswalk processes between the new sources’ data models and the OpenCitations Data Model, with the aim to define a functional and easily extendable workflow to be easily reused when it comes to incorporating new data sources, which should be:
sufficiently generic to establish a globally unique procedure;
customizable enough to capture the necessary information within each of the specific data models and formats.
As a solution, we decided to use OpenCitations Meta, the new OpenCitations database and tool for managing bibliographic data related to the publications involved in the citations. OpenCitations Meta makes it possible to assign each entity involved in a citation an internal identifier, nominally the OpenCitations Meta Identifier (OMID), to which all the associated persistent identifiers of the same publication are redirected.
As a result, the allocation of an OMID for each bibliographic resource also enabled the unambiguous identification of each citation, regardless of the persistent identifier schema originally used by the data source to identify the resources. This approach allowed us to perform data deduplication and finally make all the sources’ contributions converge into a unified index containing all the unique citations managed by OpenCitations, expressed as OMID to OMID citation links.
The revised workflow
The new workflow is based on three main components with the benefit of optimizing the process both in terms of computational cost and in terms of flexibility. As shown in Fig. 1, in a preliminary step, source-specific software converts the input dataset – structured according to the source data model – to extract two OpenCitations Data Model compliant data collections in tabular format for bibliographic metadata and citation data, respectively.
The following steps are common to the process of each dataset.
STEP 1: The bibliographic metadata collection is used as input for the META software. At this stage, it is checked whether or not the bibliographic entities have been previously integrated into our infrastructure (coming from other data sources). If so, the existing OMID is linked also to the new alternative identifiers of the new bibliographic resources. New metadata values, if any, are also integrated. A new OMID identifier is produced for entities never previously encountered, uniquely representing the bibliographic resource in OpenCitations. The outputs of the process are: (I) an updated version of the OpenCitations Meta collection that also includes the metadata of the bibliographic entities provided by the new source, and (II) a collection of provenance data. An internal database is constantly refreshed to preserve correspondence between IDs and the associated internal OMIDs.
STEP 2: Starting from the collection of citations expressed as directional links between identifiers of potentially any type (e.g., DOI-DOI, PMID-PMID, PMC-PMID, etc.), the INDEX software queries the internal database mapping IDs to OMIDs to produce an updated version of the OpenCitations Index: unique citations expressed as OMID-OMID links in different formats, accompanied by their corresponding provenance data.
Fig. 1: An overview of the data ingestion workflow, starting from the data source-specific conversion and production of citations and bibliographic metadata tables, progressing through the META process and the assignation of an OMID identifier to each bibliographic record involved in a citation, and culminating with the exposition of the OpenCitations Index collection of OMID-OMID unique citations.
What we have now: The OpenCitations Index
From now on, OpenCitations will no longer display an index of citation data for each source. Instead, we will publish a single collection of citations into which the contributions from each of the sources will flow, which we will simply call ‘The OpenCitations Index‘. The first version of this unified index of OMID-OMID citations is posted on Figshare. It was produced in RDF, CSV, and SCHOLIX formats, together with a collection of its provenance information, provided in RDF and CSV formats. For each citation, it is possible to trace the source of the information by consulting the Provenance data collection, thanks to the http://www.w3.org/ns/prov#atLocation property, which defines the location of each citation.
This new solution has the benefit of simplifying the consultation of the data maintained by our infrastructure without reducing the information content. In addition, by including efficient handling of the deduplication problem, the new Index not only provides accurate data on the exact number of unique citations exposed by the framework but also verifies the individual contribution of each source, as well as their overlapping data (Fig. 2).
Fig. 2: An overview of the number of citations stored in the OpenCitations Index as of October 31, 2023. The diagonal cells in the table (highlighted in yellow) show the unique contribution of each collection to the OpenCitations Index, while the other cells represent the citations that are shared between the collections. More in detail, the green cells show the overall input of each source, while the pink cells represent the number of overlapping citations between two data sources.
Currently, the Index contains almost 2 billion unique citations. By the end of November, a new version of the collection will be published, including the contribution of the new Japan Link Centre (JaLC) source.
How to access the OpenCitations Index data
To maximize the reuse of the exposed information and to ensure the greatest possible interoperability, the collection will always be published on Figshare in all formats listed above. In addition, the data will be accessible via an API, a SPARQL endpoint, and a web interface.
The redesign of the ingestion workflow marks a fundamental step for OpenCitations towards a more intuitive and simple access to our services while always preserving and improving the quality of our data. If you need further information on how the new workflow works, please visit our website, contact us at contact@opencitations.net or leave feedback and/or suggestions in the dedicated card on our public roadmap to help us improve our services and communications. Thank you!
In OpenCitations, we like to define our infrastructure organization as “community-based” and “community-driven”, and we really mean it. The support coming from the number of academic libraries and consortia coming after OpenCitations’ involvement in the 2nd SCOSS funding cycle has made it possible, starting from 2020, to make OpenCitations develop from a small university project based on time-limited grant incomes to being an open infrastructure globally recognized for the provision of open citation data and bibliographical metadata. We want to thank all our members and donors, for trusting our mission and sustaining OpenCitations activities with their continuous and generous support, despite the pandemic and post-pandemic times.
While retracing our work in the last three years, we are astonished by the achievements our team has accomplished, and by how in such a limited time frame OpenCitations has approached David Shotton’s initial vision (who is one of the co-directors of OpenCitations), when he first shaped the project back in 2010. Here are just some of the technical developments that have marked the last years:
in 2022, we released the two new OpenCitations indexes of open citations, DOCI (citations from DataCite) and POCI (citations from PubMed);
we expanded our collection besides the citation data by releasing OpenCitations Meta, a database storing and delivering bibliographic metadata for all the publications in the OpenCitations Indexes, including the publication’s title, type, venue (e.g. journal name), volume number, issue number, page numbers, publication date, identifiers and details of the main actors involved in the document’s publication (the names of the authors, editors, and publishers);
as of October 2023, OpenCitations Indexes contain information on 1.82 billionunique open citations.
However, the most significant achievements for OpenCiations in the last years have been the creation of a prolific network of collaborations with other Open Science projects, such as OpenAIRE-Nexus, RISIS2 and GraspOS, and the establishment of a structured team, involving young researchers and PhD students, whose work at the University of Bologna has made it possible to work on the technical developments day by day.
Our results are a strong indicator of the growing sensibility on the theme of the open provision of bibliographical metadata and citation data, of which Open Citations is at the forefront as a founding member of the Initiative for Open Citations (I4OC) and the Initiative for Open Abstracts (I4OA). The effort and awareness campaigns led by these initiatives, by DORA and the Open Science community as a whole, have led more and more publishers to a change of heart and to open their reference lists. OpenCitations is an integral part of an ongoing process of transformation of the research environment, and we have collected and interpreted some of the needs of the academic community to plan our future activities and developments. We still need your help and support to make it possible to maintain and improve our infrastructure and to sustain the team working at OpenCitations.
If you believe in
the importance of open bibliographic data for the creation of reproducible metrics for research assessment exercises
the power of the scholarly community to change existing practice by reclaiming ownership of its own data– and you want to become an active part of this change
please consider supporting OpenCitations either via membership or donation. You can find all the information on membership on our website at https://opencitations.net/membership, or you can ask for information by contacting us at membership@opencitations.net.
Together, we can work to create an open and inclusive future for science and research.
Last April, Martin Fenner launched Rogue Scholar, an archive of science blogs aiming to index full-text of blog posts, establish a full-text search, and register DOIs and metadata for all posts. Rogue Scholar works with all blogging platforms that publish scholarly content and have an RSS or Atom feed with full-text content distributed under a Creative Commons Attribution (CC-BY 4.0) license.
Rogue Scholar currently features 40 blogs, including the OpenCitations blog, with more than 1,000 blog posts that are available via full-text search, with DOIs linking to the original post on one of 40 science blogs. By exploring the OpenCitations blog’s profile on Rogue Scholar, you will find the last 40 posts with summaries (derived from the information you get in the RSS feed), and by clicking on the DOI you will be redirected to the full post on the blog. The DOI metadata include abstract, language, license, and (OECD Fields of Science) subject category for all posts.
Rogue Scholar is growing day by day, and the increasing involvement of science blogs – from different disciplines and various languages – demonstrates that “a central archive of science blogs with full-text content, and DOIs for all blog posts with relevant metadata is feasible, making an important contribution toOpen Scholarly infrastructure”.
Thanks to a recently launchedMastodon instance at Rogue Scholar Social, the OpenCitations blog has now its own Mastodon feed, where you can keep yourself updated about the last posts of the OpenCitations blog, by finding summaries and the related DOIs linking to the full post – and you can also boost and comment, of course! Please follow us at https://rogue-scholar.social/@opencitations to not miss anything.
If you are managing a Science Blog and are interested in adding it to the Rogue Scholar archive, or if you are just interested in the topic of metadata for scholarly blogs, please contact info@front-matter.io
Last March, the Coalition for Advancing Research Assessment (CoARA) launched its call for members to propose Working Groups and National Chapters. The aim of the call (which was closed in June) was to foster the creation of Working Groups that would work as ‘communities of practice’ to enable systemic reform of research assessment by providing mutual learning and collaboration on specific thematic areas.
A group of 23 Coalition members, including University of Bologna’s personnel working at OpenCitations, collaborated in designing and proposing the CoARA Working Group Towards Open Infrastructures for Responsible Research Assessment (OI4RRA), focusing on having open infrastructures for making research assessment more transparent and responsible, and thus enabling the research community to be in full control of the data and indicators it relies on in assessments.
We are now thrilled to announce that the proposed Working Group has been accepted, and will start its activities in the next months, with the mission to “enable institutions to move from proprietary infrastructure and research information, to open alternatives–in support of the transition to responsible research assessment practices. This effort will take into consideration the wide range of research outputs and open science practices and address the diversity of the global research community”.
The CoARA Working Group Towards Open Infrastructures for Responsible Research Assessment will work to facilitate the use of existing open infrastructures, -, with the aim to make it possible a transition to a fully OI4RRA ecosystem – interconnected, decentralised and open – that is fit to serve existing and emerging needs of reformed RRA agendas.
For more information visit the dedicated section on CoARA’s website, and read the full list of participants in OI4RRA here.
The four supported infrastructures (OpenCitations, the DOAB, LA Referencia and ROR) “were evaluated by the jury composed by SCOSS, then according to the exemplary criteria of the Committee for the Open Science, which notably guarantee transparency and the participation of the scientific communities in their governance”.
Since 2020, the FNSO has acknowledged OpenCitations as an infrastructure worth its financial support, thanks to its mission of disseminating bibliographic and citation metadata in open access with a level of quality and coverage, thus providing a workable, free and open alternative to the academic community’s current dependency on proprietary tools. OpenCitations’ work therefore frees up citation analysis, promotes the evolution of bibliometric indicators and the broadening knowledge of science.
The FNSO is now contributing to OpenCitations with recurring funding for 2023, 2024 and 2025 for an annual amount of €75,000. This generous support will be crucial in sustaining the maintenance and development of OpenCitations’ technical infrastructure, and in supporting the future activities of the OpenCitations team, that are publicly displayed in the OpenCitations Roadmap.
We are extremely honoured and grateful to the French National Fund for Open Science for renewing the pledge of such a portion of its open science budget to support our work.
We are pleased to announce that, after two online editions, the 2023 edition of the Workshop on Open Citations and Open Scholarly Metadata will come back to Bologna, on 26-27 October 2023. – https://workshop-oc.github.io.
During the two-day event, researchers, policy-makers and scholarly publishers will gather in the historical location of the University of Bologna to take part in the plenary presentations and discussions around this year’s theme:
The value of open scholarly metadata for research assessment purposes.
Participation
If you wish to participate in the Workshop on Open Citations and Open Scholarly Metadata 2023 as an attendee, please fill in the form by providing the requested information and a short bio to apply for the event. You will receive a notification of acceptance by 25 June. In case of oversubscriptions, the organisers will select attendees from among those who have applied.
If you wish to talk in the Workshop of Open Citations and Open Scholarly Metadata 2023, please fill in both the first part and the second part of the application form to submit a contribution (max 500 words) that fits this year’s theme “The value of open scholarly metadata for research assessment purposes”. The organizing committee will decide if the selected submissions will involve either a talk of 10-minute duration, with a 5-minute discussion following, or a poster presentation.
Application deadline: 21 May 2023 11 June 2023 ( h. 23:59 AoE ).
Fees and expenses
For the accepted attendees and contributors, we request a small registration fee (VAT included) of €100 to cover expenses (€25 for students). We will provide lunches and refreshments on all days, and a free workshop dinner on Thursday 26 October.
Those attending will be expected to cover the cost of their own travel and accommodation, and a list of recommended hotels and guest houses is available here.
Details of how to pay will be sent with the notification of acceptance together with information to finalize the registration.
Please circulate this invitation to any colleagues that you think might be interested in attending this workshop.
Venue
Bologna is home to numerous prestigious cultural, economic and political institutions as well as one of the most impressive trade fair districts in Europe. In 2000 it was declared the European capital of culture, and in 2006, a UNESCO “city of music”. Bologna’s porticoes have been listed on the UNESCO World Heritage List in 2021.
The University of Bologna is the oldest university in the western world, and one of the largest universities in Italy (with about 90,000 enrolled students).
The workshop will take place at the University of Bologna in the heart of the city – the Department of History, Cultures, and Civilization (Italian translation: Dipartimento di Storia, Culture e Civiltà), Piazza S. Giovanni in Monte, 2, Room “Aula Prodi”.
The event will be also live-streamed.
List of organizers
Giovanni Colavizza (University of Amsterdam; ScholarIndex)
Chiara Di Giambattista (University of Bologna; OpenCitations)
Ivan Heibi (University of Bologna; OpenCitations)
Philipp Mayr (GESIS – Leibniz-Institute for the Social Sciences; EXCite/OUTCite)
Silvio Peroni (University of Bologna; OpenCitations)
Matteo Romanello (Swiss Federal Institute of Technology in Lausanne; ScholarIndex)
David Shotton (University of Oxford; OpenCitations)
Ludo Waltman (Centre for Science and Technology Studies, Leiden University; VOSViewer)
OpenCitations is seeking applicants for a one-year Research Fellow position to be held from April 2023, for which the application closing deadline is 28 February 2023.
Currently, the amount and complexity of the data made available by OpenCitations opens up several issues related to the improvement, scalability and optimisation of its infrastructure. Therefore, it is crucial to study and customise recent approaches for managing Big Data to create a knowledge base to build decentralised, scalable, long-lasting and easily-customizable services.
The goal of the Research Fellowship is
to study the current limitations and possible improvements to introduce in the OpenCitations infrastructure
to reengineer the current infrastructure to make it more scalable, reliable, interoperable, reusable and distributed.
Thus, the Research Fellow is expected to address issues related to the provision of Web services, the management of distributed and heterogeneous databases and services, data conversion and ingestion processes, parallel computing and security. Particular attention will be given to data preservation and the long-term maintenance and update of the infrastructure.
Requirements
The minimal formal requirement for this position is a Master’s degree in Computer Science, Computer Science and Engineering, Telecommunications Engineering, Digital Humanities or equivalent.
Moreover, applicants are expected to have
sysadmin skills
computer programming skills
the ability to read, write and speak in good English
It is highly desirable for the applicants to have
demonstrable expertise in using and managing Linux servers (especially Debian and Raspbian), container orchestrator systems (e.g. Kubernetes), infrastructure-as-code systems (e.g. Terraform), Web servers implementing FastGCI (especially lighttpd), graph databases (especially Blazegraph), Python programming and Python Web Application Frameworks (especially web.py and Flask), Git-based version-control systems (especially GitHub);
a strong and demonstrable commitment to open science
demonstrable knowledge of Semantic Web technologies, Linked Data and Web technologies
Teamwork abilities and a good knowledge of Italian would also be very beneficial.
How to apply
The Research Fellowship application (written either in Italian or in English) should minimally comprise the following:
a cover letter of application, motivating why the candidate is applying for this position;
a full Curriculum Vitae containing information about prior scientific and professional jobs and the scientific production of the candidate;
a public portfolio of software, projects and activities undertaken within the past ten years, with a clear indication of the applicant’s role in each.
The Call for Applications (in Italian and in English) is available online on the website of the University of Bologna. It also includes an attachment with a description of OpenCitations and of the activities related to the position. The position has a net salary (exempt from income tax, after deduction of social security contributions) in excess of 23K euros per year. As indicated in the Call for Applications, candidates need to apply exclusively through the University of Bologna web portal.
This blog post is the first of a series dedicated to the description and promotion of OpenCitations Meta.
In addition to OpenCitations’ Citation Indexes, OpenCitations is pleased to announce a new service: OpenCitations Meta, a database which stores and delivers bibliographic metadata for all publications involved in the OpenCitations citation indexes.
For each publication, the metadata exposed by OpenCitations Meta includes the publication’s title, type, venue (e.g. journal name), volume number, issue number, page numbers, publication date, and identifiers such as Digital Object Identifiers (DOIs) and PubMed Identifiers (PMIDs). In addition, OpenCitations Meta includes details of the main actors involved in the publication of the document, i.e., the names of the authors, editor, and publisher, each with its own additional metadata and identifier (e.g. ORCID).
Why OpenCitations Meta?
OpenCitations Meta represents a major infrastructural advance for OpenCitations, since it addresses and overcomes some of the limitations previously experienced, providing three major benefits:
1. It permits OpenCitations to respond more quickly to user requests for information.
The OpenCitations Citation Indexes contain citation-related metadata, such as the identifiers for the citing and cited publications, the citation timespan, and other citation-specific metadata, for example whether or not the citation is a self-citation. However, metadata for the citing and cited publications were hitherto not stored by OpenCitations, but rather obtained by on-the-fly API calls to external services such as Crossref, Datacite and ORCID. This dependence on responses from external services significantly slowed the delivery of the required information to users. Since OpenCitations Meta stores in-house the same bibliographic metadata for the citing and cited publications as was previously obtained by those external API calls, the former temporal limitation is now alleviated, thereby accelerating response times for requests made to the OpenCitations REST API services, and thus better supporting our users.
2. It permits OpenCitations to index citations involving publications that lack DOIs.
The second problem that OpenCitations Meta addresses goes beyond the OpenCitations infrastructure and addresses a more general issue of digital publishing, particularly in the Humanities, namely that many scholarly publications lack persistent identifiers such as DOIs and PMIDs. The citations indexed by OpenCitations are themselves treated as first-class data entities, each bearing a unique persistent Open Citation Identifier. According to the Open Citation Identifier definition [1], the entities linked by an indexed citation need to be identified by a persistent identifier (PID) from a recognised scheme such as the Digital Object Identifier scheme. For example, COCI [2] records the DOIs of the citing and cited entities. However, the association of DOIs with published documents is not uniformly spread across all scholarly fields. Indeed, in Scopus and the Web of Science Core Collection, only 50% of the current publications in the Art and Humanities are associated with a DOI [3]. In addition, in many fields, particularly in the Humanities, references are required to pre-digital historical primary sources that lack PIDs. OpenCitations Meta solves this problem by assigning a unique OpenCitations Meta Identifier (OMID) to each document. In this way, it can record the metadata of publications lacking an external identifier and store the citations involving them in one of the OpenCitations Indexes.
3. Use of the OpenCitations Meta Identifier permits de-duplication of records of bibliographic resources having more than one external identifier, such as a DOI and a PMID.
While many scholarly publications lack external PIDs, many others will have more than one external PID, for example a DOI for the record of that publication in Crossref, and a PMID for the record of that same publication in PubMed. This is perfectly legitimate. Since OpenCitations Meta assigns a unique OpenCitations Meta Identifier (OMID) to every entry, and in addition records all external identifiers already assigned to that publication, for example its DOI and its PMID, this permits the automatic de-duplication of such publications within OpenCitations Meta.
The data model
OpenCitations uses Semantic Web technologies to encode all its data, including the bibliographic metadata now stored in OpenCitations Meta. For this purpose, the OpenCitations Data Model (OCDM) [4] uses classes and properties defined in the SPAR Ontologies to represent:
bibliographic entities (fabio:Expression), e.g. a journal article
identifiers (datacite:Identifier), e.g. a DOI
agent roles (pro:RoleInTime), e.g. an author
responsible agents (foaf:Agent), e.g. a person
publication format details (fabio:Manifestation), e.g. first and last pages
Figure 1 depicts relationships between some of the various entities.
Figure 1. A small subset of the OCDM used in OC Meta. Yellow rectangles represent classes, green polygons represent data types, while blue and green arrows represent object properties and data properties, respectively
In addition to storing data, great importance is given to recording provenance and change-tracking of OpenCitations Meta entries, including the agent who processed a specific entity, i.e. creating, deleting, modifying or merging it, the date and time on which this action was performed, and the primary source of the data.
The data
At the release date, 20th December 2022, OpenCitations Meta is using Crossref as its primary source, with the purpose of hosting the metadata describing all citing and cited publications involved in the 1,392,036,835 citations within COCI [2]. From a quantitative point of view, OpenCitations Meta presently contains metadata describing 87,321,593 bibliographic entities, 277,750,235 authors, 2,359,301 editors, 17,268 publishers, and 710,226 publication venues (e.g. journal names). Editors and authors have been counted by their roles, without at this stage disambiguating individuals with the same name. Conversely, bibliographic entities, publishers, and publication venues were counted by their OMIDs. In total, the OpenCitations Meta triplestore presently contains 3,298,335,581 triples.
In the following days, OpenCitations Meta will be expanded to include bibliographic metadata for all citing and cited publications involved in the 169,822,752 citations from DataCite within DOCI, released on 13th December 2022.
Table 1 lists the various types of bibliographic resource represented in OpenCitations Meta. The current dataset contains mostly journal articles (60,683,841), which exceed the number of book chapters (6,288,351) by about ten times and the number of conference proceedings articles (4,917,568) by about twelve times.
OpenCitations Meta allows the users to explore the contained metadata either via SPARQL (https://opencitations.net/meta/sparql) or via the OpenCitations Meta REST API (https://opencitations.net/meta/api/v1). In particular, the API will retrieve a list of bibliographic resources and related metadata starting from one or more identifiers including an OpenCitations Meta Identifier (OMID), an author’s ORCID, or an editor’s ORCID.
Finally, all the metadata and provenance information present in OpenCitations Meta are available as dumps in RDF (JSON-LD) or CSV format under a CC0 licence. Every time a citation index is updated, we will update OpenCitations Meta.
Conclusion
OpenCitations Meta makes search operations on the metadata of scholarly publications involved in the citations indexed in the OpenCitations Citation Indexes faster, since the metadata are now held in-house. The use of OpenCitations Meta Identifiers (OMIDs) permits OpenCitations Meta to act as a mapping hub to disambiguate and unify information on single publications identified by more than one external identifier, and makes it possible to characterise citations involving resources lacking an external identifier.
In the future, we will introduce a new API operation to perform text searches. Moreover, OpenCitations Meta will incorporate metadata from other sources in addition to Crossref. As mentioned above, work is already under way to ingest bibliographic metadata from Datacite for the publications involved in the citations newly indexed in DOCI. This will soon be followed with similar OpenCitations Meta entries relating to a new citation index, POCI, containing citations from PubMed, to be released later this year. PubMed metadata will be made available by February 2023.
Heibi, I., Peroni, S. & Shotton, D. Software review: COCI, the OpenCitations Index of Crossref open DOI-to-DOI citations. Scientometrics 121, 1213–1228 (2019). https://doi.org/10.1007/s11192-019-03217-6
Gorraiz, J., Melero-Fuentes, D., Gumpenberger, C., & Valderrama-Zurián, J.-C. (2016). Availability of digital object identifiers (DOIs) in Web of Science and Scopus. Journal of Informetrics, 10 (1), 98–10. https://doi.org/10.1016/j.joi.2015.11.008
Fig. 1: An overview of the data ingestion workflow, starting from the data source-specific conversion and production of citations and bibliographic metadata tables, progressing through the META process and the assignation of an OMID identifier to each bibliographic record involved in a citation, and culminating with the exposition of the OpenCitations Index collection of OMID-OMID unique citations.
