This post was first published on QUERTY: musings from the rabbit hole, a blog by Silvio Peroni In the scholarly ecosystem, a bibliographic citation is a conceptual directional link from a citing entity to a cited entity, used to acknowledge or ascribe credit for the contribution made by the author(s) of the cited entity.

Silvio Peroni

*This post was first published on *[*QUERTY: musings from the
rabbit* *hole*](https://querty.hypotheses.org/535){data-type="URL"
data-id="https://querty.hypotheses.org/535" target="_blank"
rel="noreferrer noopener"}, *a blog by Silvio Peroni*

In the scholarly ecosystem, a bibliographic citation is
a *conceptual* directional link from a citing entity to a cited entity,
used to acknowledge or ascribe credit for the contribution made by the
author(s) of the cited entity. Citations are one of the core elements of
scholarly communication. They enable the integration of our independent
research endeavours into a global graph of relationships that can be
used, for instance, to analyse how scholarly knowledge develops over
time, assess scholars' influence, and make wise decisions about research
investment.

### A copyrighted fact {#a-copyrighted-fact .wp-block-heading}

However, as citation data, i.e. pieces of *factual* information aiming
at identifying entities and relationships among them, are of great value
to the scholarly community, [it has been a "scandal" that they have not
been recognised as part of the
commons](https://doi.org/10.1038/502295a){target="_blank"
rel="noreferrer noopener"}. Indeed, only recently we have seen some
efforts -- such as the [Initiative for Open Citations
(I4OC)](https://i4oc.org/){rel="noreferrer noopener" target="_blank"} --
that have tried to change the *behind-the-paywall status quo* enforced
by the companies controlling the major citation indexes used worldwide,
convincing scholarly publishers to support the unrestricted availability
of scholarly citation data by publishing them in suitable open
infrastructures, such
as [Crossref](https://crossref.org/){rel="noreferrer noopener"
target="_blank"} and [DataCite](https://datacite.org/){rel="noreferrer noopener"
target="_blank"}.

Of course, as for many other kinds of data, putting bibliographic and
citation data behind a paywall is a thread to enabling the full
reproducibility of research studies based on them (e.g. in
bibliometrics, scientometrics, and science of science domains), even
when such studies are published in open access articles. For instance,
the [results of a recent open access article published on *Digital
Scholarship in the
Humanities*](https://doi.org/10.1093/llc/fqac016){target="_blank"
rel="noreferrer noopener"}, which aimed to analyse the citation
behaviour of Digital Humanities (DH) research across different
proprietary and open citation databases, are not fully reproducible
since the majority of the databases used -- namely Scopus, Web of
Science, and Dimensions -- do not make their bibliographic and citation
data openly available.

In addition, the coverage of publications and related citations in
specific disciplines, particularly those within the Social Sciences and
the Humanities (SSH),
is [inadequate](https://doi.org/10.1007/s00799-022-00327-0) [compared
to](https://doi.org/10.1007/s11192-020-03690-4){rel="noreferrer noopener"
target="_blank"} [other](https://doi.org/10.1007/s11192-021-03948-5){rel="noreferrer noopener"
target="_blank"} [fields](https://doi.org/10.1162/qss_a_00112). Usually,
this is due to the limited availability of born-digital publications
accompanied by a wide variety of publication languages, publication
types (e.g. monographs), and complex referencing practices that may
limit their automatic processing and citation extraction. As a side
effect, such a partial coverage may result in a considerable bias when
analysing SSH disciplines compared to STEM disciplines that usually have
better coverage in existing citation databases.

### Reforming research assessment {#reforming-research-assessment .wp-block-heading}

All these scenarios have at least another negative effect on the area
strictly concerned with the research assessment, which often uses
quantitative metrics based on citation data to evaluate articles,
people, and institutions. Indeed, the unavailability and partial
coverage of bibliographic and citation data create
an *artificial* barrier to the transparency of the processes used to
decide the careers of scholars in terms of research, funding, and
promotions.

In the past years, several initiatives around the world have highlighted
the importance of reforming research assessment exercises, such as those
summarised in the [following
figure](https://querty.hypotheses.org/535#fig1): the *[Frech National
Plan for Open
Science](https://www.ouvrirlascience.fr/national-plan-for-open-science-4th-july-2018/){rel="noreferrer noopener"
target="_blank"}*, the *[San Francisco Declaration on Research
Assessment](https://sfdora.org/){rel="noreferrer noopener"
target="_blank"}*, the *[Leiden Manifesto for Research
Metrics](http://www.leidenmanifesto.org/){rel="noreferrer noopener"
target="_blank"}*, and the recent [proposal for a reform of the research
assessment system by the European
Commission](https://doi.org/10.2777/707440){rel="noreferrer noopener"
target="_blank"}. All these initiatives agree on a few essential
characteristics necessary for having a trustful assessment system: 

- to be open and transparent by
 providing *machine-readable*, *unrestricted* and *reusable *data and
 methods for calculating the metrics used in research assessment
 exercises, and 
- to leave to the *research community*, instead of commercial players,
 the control and ownership of the crucial infrastructures and tools
 used to retrieve, use and analyse such data within research assessment
 systems. 

Thus, the leading guideline that can be abstracted is to follow Open
Science practices *even when assessing research* and not only when
performing research.

<figure id="fig1" class="wp-block-image">
<img
src="https://lh4.googleusercontent.com/bCY3ns_ltacCodQ_rCJ2HnT6WlolXUDkDIAywh0JvPFDTFgeeSN0GXAfcNPdB4H0wqdoMdzlwmb490kwFNXgn2xLdbaQNTw-zcd2_-M6a-KKQoFx-hbP8FzedyCUtagkLGFn8-bzn5XafmU6J8AgRyjJnoIBFFdimFBjaY_YmgpfrHe9YEzarrp3Bw"
title="Figure 1" decoding="async"
alt="Some initiatives pushing for reforming the principles behind research assessment systems." />
<figcaption aria-hidden="true">Some initiatives pushing for reforming
the principles behind research assessment systems.</figcaption>
</figure>

### Introducing OpenCitations {#introducing-opencitations .wp-block-heading}

Within this
context, [OpenCitations](https://opencitations.net/){rel="noreferrer noopener"
target="_blank"} (full disclosure: I am one of its directors) plays an
important role, acting as a key infrastructure component for global Open
Science, and pushes for actively involving universities, scholarly
libraries and publishers, infrastructures, governments and international
organisations, research funders, developers, academic policy-makers,
independent scholars and ordinary citizens. The mission of OpenCitations
is to harvest and openly publish accurate and comprehensive metadata
describing the world's academic publications and the scholarly citations
that link them, with the greatest possible global coverage and subject
scope, encompassing both traditional and non-traditional publications,
and with a breadth and depth that surpasses existing sources of such
metadata, while maintaining the highest standards of accuracy and
accompanying all its records with rich provenance information, and
providing this information, both in human-readable form and in
interoperable machine-readable Linked Open Data formats, under open
licenses at zero cost and without restriction for third-party analysis
and re-use.

For OpenCitations, *open* is the crucial value and the final purpose. It
is the distinctive mark and founding principle that everything
OpenCitations provide -- data, services and software -- is open and free
and will always remain so. OpenCitations fully espouses the aims and
vision of the UNESCO Recommendations on Open Science, complies with the
FAIR data principles, and promotes and practises the Initiative for Open
Citations recommendation that citation data, in particular, should be
Structured, Separable, and Open. 

The most important collection of such open citation data is [COCI, the
OpenCitations Index of Crossref open DOI-to-DOI
citations](https://w3id.org/oc/index/coci){target="_blank"
rel="noreferrer noopener"}. The last release, dated August 2022,
contains more than 1.36 billion citation links between more than 75
million bibliographic entities that can be accessed programmatically
using its REST API, queried via the related SPARQL endpoint, and
downloaded in full as dumps in different formats (CSV, JSON, and RDF). 

<figure id="fig2" class="wp-block-image">
<img
src="https://lh4.googleusercontent.com/wjet3GPewBPF72CxxmS4I_unxHPzExX8YxW0LLBOi8sHnm-dZNf1SfdV8CfqEw6iL5y4Q9ryGDhmUriJT6p249hZOEKVJrSiF8K1jCZJiicgEb-KZ6oGyoBCk5uVjIuL2_WfYCbgxH_CnHMxhLHbJWzE_wHeUGwyGWgnk4y5ZYJUKAtPJ39gu3VS7g"
title="Figure 2" decoding="async"
alt="Collaborations between OpenCitations and other Open Science infrastructures and services." />
<figcaption aria-hidden="true">Collaborations between OpenCitations and
other Open Science infrastructures and services.</figcaption>
</figure>

In addition to the publication of citation data, a considerable effort
has been dedicated to collaborating with other Open Science
infrastructures working in the scholarly ecosystem, as summarised in
the [figure above](https://querty.hypotheses.org/535#fig2). Since 2020,
OpenCitations has significantly benefited from the scholarly community
that resulted from the 2019 selection by the [Global Sustainability
Coalition for Open Science Services
(SCOSS)](https://scoss.org/){rel="noreferrer noopener"
target="_blank"} of OpenCitations as a scholarly infrastructure worthy
of financial support. The community funding permitted the appointments
of people dedicated to the administration, communication, community
development, and maintenance and improvement of the OpenCitations
software and the computational infrastructure on which it runs. In
addition, OpenCitations started its involvement
with [OpenAIRE](https://www.openaire.eu/){rel="noreferrer noopener"
target="_blank"} and the [European Open Science Cloud
(EOSC)](https://eosc-portal.eu/){rel="noreferrer noopener"
target="_blank"}, and it is collaborating with other funded projects
project such
as [RISIS2](https://www.risis2.eu/){rel="noreferrer noopener"
target="_blank"}, [OutCite](https://excite.informatik.uni-stuttgart.de/){rel="noreferrer noopener"
target="_blank"}, [OPTIMETA](https://projects.tib.eu/optimeta/en/){rel="noreferrer noopener"
target="_blank"} and [B!SON](https://projects.tib.eu/bison/en/project/){rel="noreferrer noopener"
target="_blank"}.

While OpenCitations is currently providing a good set of citation data,
which is already [approaching parity with other commercial citation
databases](https://opencitations.hypotheses.org/1420){rel="noreferrer noopener"
target="_blank"} and that has already been used in a few studies for
research purposes, there is still a margin for improvement. Currently,
the citations included in the OpenCitations Indexes come mainly from
Crossref data, one of the biggest open reference providers. However,
Crossref does not cover all the publishers of DOI-based resources.
Indeed, other DOI providers, in some cases, expose citation relations in
their metadata, such as DataCite. In addition, DOI-based publications
represent just a limited set of all the bibliographic entities published
in the scholarly ecosystem. Other identifier schemas have been used to
identify bibliographic entities -- and, for some publications, there not
exist identifiers at all!

Thus, to address these two issues, OpenCitations is working on expanding
its coverage according to two different directions. On the one hand,
OpenCitations is developing two new citation indexes of open references
based on the holdings of DataCite and the [National Institute of Health
Open Citation
Collection](https://doi.org/10.1371/journal.pbio.3000385){rel="noreferrer noopener"
target="_blank"}, which, together with COCI, will be cross-searchable
through the [Unifying OpenCitations REST
API](https://w3id.org/oc/index/api/v1/){rel="noreferrer noopener"
target="_blank"}. 

On the other hand, OpenCitations has started working to create a new
database entitled OpenCitations Meta, which will provide three major
benefits. First, it will permit storing in-house bibliographic metadata
for the citing and cited entities involved in all OpenCitations Indexes,
including author identifiers using ORCID and VIAF identifier schemes
where available. Second, it will provide better query performance than
the present API system, which obtains bibliographic metadata on-the-fly
by live API calls to external services, such as Crossref and DataCite
APIs. Finally, it will permit indexing citations involving entities
lacking DOIs, by providing them OpenCitations Meta Identifiers.

This last collection, combined with automatic tools for citation
extraction from digital formats, is crucial for increasing the coverage
of underrepresented disciplines and fields in bibliographic databases,
such as SSH publications. One of the OpenCitations' goals is to reduce
this gap in citation coverage by setting up crowdsourcing workflows for
ingesting missing citation data from the scholarly community (e.g.
libraries and publishers). In the future, another contribution will be
to set up tools for automatic extraction of citations that can also
support small and local publishers, crucial assets for SSH research,
that may find difficulties in carrying out citation extraction tasks on
their own since using and maintaining a tool (or paying a company
addressing those tasks on behalf of the publisher) requires extra costs
beyond publishers' finances.

To conclude: OpenCitations is one piece of a puzzle that is working to
change existing scholarly practices to create an open and inclusive
future for science and research in which the scholarly community owns
and is responsible for its own data.

***Disclaimer:** This text was created during the [TRIPLE Booksprint
"The role of open metadata in the SSH scholarly
communication"](https://project.gotriple.eu/events/triple-booksprint/){rel="noreferrer noopener"
target="_blank"} and is intended to be a contribution to the "Guidelines
on the research data in the humanities" deliverable (8.5) of the [TRIPLE
project](https://project.gotriple.eu/){rel="noreferrer noopener"
target="_blank"} which will be made publicly available under the CC-BY
4.0 license.*

*This post was first published on *

 QUERTY: musings from the rabbit


 hole

,

 a blog by Silvio Peroni

In the scholarly ecosystem, a bibliographic citation is a

 conceptual

directional link from a citing entity to a cited entity, used to acknowledge or ascribe credit for the contribution made by the author(s) of the cited entity.

Messaggi di Rogue Scholar

Transparency meets open citations