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<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>A review of ontologies for describing scholarly and scienti c documents</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Almudena Ruiz-Iniesta</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Oscar Corcho</string-name>
          <email>ocorchog@fi.upm.es</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Ontology Engineering Group, Facultad de Informatica Universidad Politecnica de Madrid</institution>
          ,
          <addr-line>Madrid</addr-line>
          ,
          <country country="ES">Spain</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>Several ontologies have been created in the last years for the semantic annotation of scholarly publications and scienti c documents. This rich variety of ontologies makes it di cult for those willing to annotate their documents to know which ones they should select for such activity. This paper presents a classi cation and description of these state-of-the-art ontologies, together with the rationale behind the di erent approaches. Finally, we provide an example of how some of these ontologies can be used for the annotation of a scienti c document.</p>
      </abstract>
      <kwd-group>
        <kwd>ontology</kwd>
        <kwd>document semantics</kwd>
        <kwd>semantic publishing</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>Introduction</title>
      <p>
        Semantic publishing [
        <xref ref-type="bibr" rid="ref1 ref2">1,2</xref>
        ] can be de ned as the activity of enhancing a
document (e.g. a journal article) with semantic annotations, providing a way to
understand the meaning of the published information and enabling the linking
to related documents. Semantic publications o er a better access to both their
content and metadata describing the entire documents, their structure, their
rhetorical elements and related information. Several ontologies have been
created to support this activity in di erent scholarly domains, e.g., EXPO [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ] in
the scienti c experiments domain, OMDoc as a markup format and data model
for Open Mathematical Documents [4], the SWAN ontology for modelling the
scienti c discourse, developed in the context of building a series of applications
for biomedical research [5]. However, the variety of works that describe
documents in di erent domains makes it di cult to choose the best ontology for the
annotation of scienti c papers, besides the obvious use of Dublin Core Terms1.
Moreover, there are no general conventions or rules on how to use the
existing ontologies in semantic publishing. In order to shed light on this variety of
works, in this paper we review the most relevant ontologies for describing
scholarly publications and we also present other vocabularies that allow embedding
formal metadata in documents using markup languages.
      </p>
      <p>
        Therefore, the result of this work is a classi cation of the most important
ontologies for describing scholarly documents. The proposed classi cation divides
ontologies into three main groups: ontologies for describing the document
structure (sections, paragraphs, etc.), ontologies for describing the rhetorical elements
(introduction, results, etc.) and ontologies for describing bibliographies and
citations. In what follows, we expand on these ontologies, and show how they
can be employed to describe a scienti c paper. We also illustrate how some of
them could be applied to a published article from the journal Future Generation
Computer Systems, which is already encapsulated as a Research Object [
        <xref ref-type="bibr" rid="ref4">6</xref>
        ]2.
      </p>
      <p>The rest of the paper is organized as follows: Section 2 explains the main
ontologies that describe documents; Section 3 focuses on describing ontologies
for the scienti c discourse; Section 4 presents the works that attempt to annotate
the references of a document; Section 5 introduces other vocabularies that allow
annotating documents. Finally, Section 6 concludes the paper and depicts some
recommendations to annotate a scienti c document.
2</p>
    </sec>
    <sec id="sec-2">
      <title>Ontologies for describing documents</title>
      <p>In this section we describe ontologies that allow describing the structure of a
scholarly article or, more generally, of a document. Each ontology is presented
with its main characteristics (classes and properties) and an example of use.</p>
      <p>One of the earliest works in this direction was the no-longer maintained
Document ontology3, implemented in the SHOE language. This ontology focuses
only on the document type. Some of the documents types de ned in this ontology
are: Abstract, Letter, Form, Lecture, etc.</p>
      <p>
        The Ontology of Rhetorical Blocks (ORB)4 captures a coarse-grained
rhetorical structure of scienti c publications, independently of their domain. The
ontology models a publication by means of three artefacts: the header, the body and
the tail. The header is the part of the publication that models meta-information
about the publication, including title, authors, a liations, publishing venue and
abstract. The body is composed by four rhetorical blocks: introduction, methods,
results and discussion, according to the IMRAD [
        <xref ref-type="bibr" rid="ref5">7</xref>
        ] structure. Finally the tail
provides additional meta-information about the paper, related to external
references. The tail is represented by two ontological entities: acknowledgments and
references.
      </p>
      <p>
        A recent work that attempts to annotate the entire characteristics of a
document is the Semantic Publishing and Referencing Ontologies5 a set of ontologies
that allow describing books and journal articles, citations, bibliographic records,
the component parts of documents, and various aspects of the scholarly
publication process. This set of ontologies is composed by:
2 http://rohub.linkeddata.es/motifs_bundle_page-FGCS/
3 http://www.cs.umd.edu/projects/plus/SHOE/onts/docmnt1.0.html
4 http://www.w3.org/2001/sw/hcls/notes/orb/#ontology
5 SPAR, namespace http://purl.org/spar
{ FaBiO6, the FRBR-aligned Bibliographic Ontology, which allows recording
and publishing bibliographic records of scholarly documents.
{ CiTO7[
        <xref ref-type="bibr" rid="ref6">8</xref>
        ], the Citation Typing Ontology, which allows characterising
citations, both factually and rhetorically.
{ BiRO8, the Bibliographic Reference Ontology, which allows describing
bibliographic records and references, and their compilation into bibliographic
collections and reference lists.
{ C4O9, the Citation Counting and Context Characterization Ontology, which
allows the characterization of bibliographic citations in terms of their number
and their context.
{ DoCO10, Document Components Ontology, which allows describing the
component parts of a document. DoCO imports the Discourse Elements
Ontology11 and the Document Structural Patterns Ontology12.
{ PRO13, the Publishing Roles Ontology, which allows characterising the roles
of agents in the publication process.
{ PSO14, the Publishing Status Ontology, which allows characterising the
publication status of a document at each of the various stages in the publishing
process.
{ PWO15, the Publishing Work ow Ontology, which allows describing the
steps in the work ow associated with the publication of a document.
In this work we analyse those focused on describing the document content. Hence
we will describe in detail DoCO (see Section 2.1) and CiTO (see Section 4).
2.1
      </p>
      <p>DoCO, Documents Components Ontology
The DoCO ontology provides a broad number of classes and relationships that
allow describing a document based on its structure and content. DoCO imports
two ontologies: Deo and the Document Structural Patterns Ontology. Deo is an
OWL2 ontology that describes the major rhetorical elements of a document.
It also provides a structured vocabulary for rhetorical elements within
documents and it uses all the rhetorical block elements from the SALT Rhetorical
Ontology [9]. The pattern ontology de nes formally patterns for segmenting a
document into atomic components, in order to be manipulated independently
and re- owed in di erent contexts.</p>
      <p>DoCO describes the vast majority of document components such as chapter,
preface, glossary, etc. Table 1 shows some of the classes from this ontology.
6 Namespace http://purl.org/spar/fabio/
7 Namespace http://purl.org/spar/cito
8 Namespace http://purl.org/spar/biro
9 Namespace http://purl.org/spar/c4o
10 Namespace http://purl.org/spar/doco
11 Namespace, http://purl.org/spar/deo
12 Namespace, http://www.essepuntato.it/2008/12/pattern
13 Namespace http://purl.org/spar/pro
14 Namespace http://purl.org/spar/pso
15 Namespace http://purl.org/spar/pwo</p>
      <p>As far as Deo is concerned, Deo supports the main rhetorical elements in a
document, e.g., Introduction, Methods, Results and Conclusions. These elements
give a de ned rhetorical structure to the paper, which assists readers to identify
the important aspects of the paper. Notice that the rhetorical organization of a
paper does not necessarily correspond neatly to its structural components
(sections, paragraphs, etc.). In this sense, Deo and DoCO complement one another.
Table 2 shows some of the most relevant classes from Deo.
acknowledgements
introduction
related work
motivation
background conclusion
future work methods</p>
      <p>results discussion
problem statement biography
3</p>
    </sec>
    <sec id="sec-3">
      <title>Scholarly and scienti c discourse ontologies</title>
      <p>The scienti c discourse has particular characteristics that are not covered by the
aforementioned ontologies. Particularly, a scienti c discourse has goals, claims,
experiments, evaluations and so on. Indeed, the reasoning of the assertion of the
scienti c document is crucial for scholarly and scienti c publishing, in proposing
hypotheses and advancing evidence in their support. Several works have been
proposed to model the discourse argumentation normally present in scienti c
articles.</p>
      <p>One of the rst works to address the modelling of the scholarly discourse
was ScholOnto[10]. The ScholOnto ontology provided a small set of conceptual
and relational types. The main class of the ontology is the Claim. All claims
are owned by an agent, and have some form of justi cation. Claims assert new
relationships with other claims, or between concepts.</p>
      <p>
        The work proposed by [11,12] identi es the main components of scienti c
investigations and construct the Core Information about Scienti c Papers (CISP)
metadata about the content of papers. The main classes proposed in CISP are:
Goal of investigation, Motivation, Object of investigation, Research method,
Experiment, Observation, Result and Conclusion. CISP metadata makes use of the
ontology of experiments EXPO16[
        <xref ref-type="bibr" rid="ref3">3</xref>
        ] as a core ontology. CISP includes eight key
16 http://expo.sourceforge.net/
classes that are presented in Table 3. Many of these key classes have additional
subclasses and properties.
goal of investigation motivation object of investigation research method
experiment observation result conclusion
      </p>
      <p>As aformentioned, CISP makes use of EXPO, a very complete ontology about
scienti c experiments. The aim of this ontology is to provide a controlled
vocabulary of scienti c experiments. For this purpose EXPO de nes over 200
concepts to allow providing a formal description of experiments for e cient analysis,
annotation and sharing of results. EXPO is able to describe computational and
physical experiments, experiments with explicit and implicit hypothesis. EXPO
de nes general classes including Scienti cExperiment, ExperimentGoal,
ExperimentTechnology, ExperimentResult, etc. (see Table 4).</p>
      <p>Inspired by EXPO and CISP metadata, the work described in [13] proposes
the Core Scienti c Concepts, CoreSCs. The CoreSCs is a scheme built upon
eleven categories at the sentence level that allows the automatic recognition of
each one of the categories in scienti c articles. The CoreSC includes: hypothesis,
motivation, goal, object, background, method, experiment, model, observation,
result and conclusion. The authors argued that these categories describe the main
components of a scienti c investigation. The rst application of this scheme has
been used to automatically annotate papers in Biochemistry and Chemistry.</p>
      <p>Other works, such as The Argument Model Ontology17, use the `Toulmin
Model of Argument' [14]. Toulmin proposed a layout containing six interrelated
components for analysing arguments: claim, evidence, warrant, backing, quali er
and rebuttal. The Argument Model Ontology models this components through
a set of 8 classes and 21 properties (see Table 5). The following snippet shows
an example of use of this ontology:
17 http://www.essepuntato.it/2011/02/argumentmodel
: sentence1 dcterms : description " We propose a catalog of
domain independent conceptual abstractions for workflow
steps that we call scientific workflow motifs " .
: sentence2 dcterms : description " We present an empirical
analysis performed over 260 scientific workflow
descriptions . " .
: argument1 a amo : Argument ;
amo : hasClaim : sentence1 ;
amo : hasEvidence : sentence2 .</p>
      <p>A very recent work is the one proposed in [15] MicroPublications18. In this
work the authors employ the Toulmin's model updated by Bart Verheij [16] and
then they propose a semantic model of scienti c argument and evidence designed
for representing the key arguments and evidence in scienti c articles.
MicroPublications proposes a model to construct an argumentation network linking
textual statements and data as evidence for claims.</p>
      <p>Beyond the works that employ a linguistic model there are other works that
are focused on describing the scienti c discourse itself and the relations among
the claims and hypotheses made by the author of the document. That is the case
of the last two works that we present here.</p>
      <p>The SWAN19 ontology [5] models the scienti c discourse. The SWAN project
is part of the Annotation Ontology [17] and it has evolved into the Domeo
annotation toolkit20 (a web application enabling users to create and share
ontologybased annotations on HTML and XML documents). The core of the SWAN
ontology models the discourse elements providing a model of assertions,
questions and hypotheses. The SWAN discourse elements are:
{ Research statements: a claim or an hypothesis.
{ Research questions: topics under investigation.
{ Structured comments: the structured representation of a comment published
in a digital resource.</p>
      <p>On the other hand the SWAN ontology also provides discourse relationships,
which are a set of relationships that can be used to build scienti c discourse.
Some of the discourse relationships are in Table 6.
18 http://purl.org/mp
19 Semantic Web Applications in Neuromedicine http://www.w3.org/TR/hcls-swan/
20 http://swan.mindinformatics.org/
refers to inconsistent with alternative to
relevant to arises from motivates
4</p>
    </sec>
    <sec id="sec-4">
      <title>Ontologies for describing bibliography and citations</title>
      <p>The references of a document play an important role in the paper. One of the
most widely used ontologies for describing bibliographic entities is BIBO, The
Bibliographic Ontology Speci cation [18]. BIBO de nes a set of classes to identify
the type of document based on its origin (journal, book, webpage, etc.), where
bibo:Document is the key class of this model. BIBO includes Dublin Core terms
to cover common needs, uses FOAF (Friend of a Friend)21 to describe authors,
and adds other classes and properties, as shown in Table 7.</p>
      <p>Although the BIBO ontology identi es in a unique way each paper, BIBO is
unable to express the history of a paper. In this sense, the work proposed by [19]
extends the BIBO ontology in order to include the internal work ow of journals,
conferences, and so forth. The result of this work allows tracking the history of
a scienti c paper.</p>
      <p>
        As mentioned in Section 2, there are other ontologies focused on describing
bibliographic entities, such as FaBiO22 [
        <xref ref-type="bibr" rid="ref6">8</xref>
        ]. FaBiO describes bibliographic entities
(e.g. books and journal articles) and their grouping (e.g. into book series and
21 http://www.foaf-project.org/
22 FaBiO http://purl.org/spar/fabio
journal issues). FaBiO classes are structured according to the FRBR schema of
Works, Expressions, Manifestations and Items [20]. FaBiO has additional
properties to extend the FRBR data model by linking the di erent parts of the FRBR
schema. The FaBiO classes are divided into four main groups: Works with 69
subclasses, Expressions with 92 subclasses, Manifestations with 10 subclasses
and Items with 4 subclasses.
      </p>
      <p>Finally, the Citation Typing Ontology23 enables the characterization of the
nature or type of citations, both factually and rhetorically. CiTO contains 41
object properties that add more information to the cite (e.g., agrees with,
corrects, likes, uses method in). CiTO allows characterising citations in three ways:
explicit citations (e.g. the reference list of a journal article), indirect citations
(e.g. a citation to a more recent paper by the same research group on the same
topic), or implicit citations (e.g. as in artistic quotations or parodies, or in cases
of plagiarism). Some of the CiTO properties are enumerated in Table 8.</p>
    </sec>
    <sec id="sec-5">
      <title>Other vocabularies for describing documents</title>
      <p>There are also other general ontologies that have been used for the annotation
of any type of documents, not just scienti c ones.</p>
      <p>The most obvious and extended one is Dublin Core Metadata Terms (DCT),
which contains fteen properties to specify the characteristics of electronic
documents (creator, date, contributor, description, format, etc). The terms in DCT
are intended to be used in combination with terms from other vocabularies, as
we saw above in the ORB vocabulary.</p>
      <p>Friend of a Friend (FOAF) is a stable ontology that contains some classes
such as Agent, Person, Organization, Group, Project, Document, Image, etc.,
and some properties to describe the instances of these classes. This vocabulary
23 CiTO, namespace http://purl.org/spar/cito
allows describing the authors of documents, their a liations and other relevant
information about them.</p>
      <p>Finally, the Semantic Web Conference Ontology24 is an ontology for
describing academic conferences. This ontology establishes how to use classes and
properties from other ontologies (FOAF, Dublin Core, SIOC25 and iCal/RDF
Calendar26) and provides some classes for things relative to conferences. Some
of these classes are: AcademicEvent, ConferenceVenuePlace, Proceedings, etc.
6</p>
    </sec>
    <sec id="sec-6">
      <title>Conclusions and recommendations</title>
      <p>24 http://data.semanticweb.org/ns/swc/ontology
25 http://sioc-project.org/
26 http://www.w3.org/TR/rdfcal/
the cited paper, because the author of the citing paper says that this document
extends their previous work.</p>
      <p>Finally, we point out how to use the FOAF ontology to annotate each one of
the authors of the document. The use of this ontology allows describing people
and their relations.</p>
      <p>In brief, we propose to use the DoCO ontology for describing the document
structure, the Deo ontology gives way to describe the vast majority of rhetorical
elements, but we believe that it is necessary to extend this ontology in order
to cover the concrete elements of the application domain. The BIBO ontology
describes references according the kind of document and all the characteristics
involved in the publication process. We propose to use the CiTO ontology for
describing the rhetoric of the citations (in this way we can establish a network
with other works). In order to describe the scienti c discourse it is necessary to
describe the most important elements of the domain (e.g. the biological domain
has probably di erent discourse elements than the computer graphics domain).
An important part in the scienti c discourse are the claims done by the author of
the paper and how they are contextualized. For this purpose we propose to use
the discourse model proposed by [11]. This model can be annotated with most
of the CiTO properties. In this sense, our nearly future work is to provide an
ontology for describing the scienti c discourse according to the aforementioned
model by doing an extension of the proposed ontologies.</p>
      <p>In this paper we have described the most relevant ontologies used for
describing scienti c documents. We have classi ed these ontologies into three main
groups, those that describe the discourse of a document (either scienti c or
generic), those that allow describing the document structure and those
dedicated to describe references and citations. At last, we have presented other
well-known vocabularies that provide generic information about any type of
document. Moreover, we have also sketched out a model for the semantic
enhancement of documents based on some of these ontologies, mainly those that
describe the document structure, their rhetorical elements and their references.</p>
    </sec>
    <sec id="sec-7">
      <title>Acknowledgments</title>
      <p>This work is supported by the FP7 European project Dr Inventor FP7-611383.
doco:title</p>
      <p>Common motifs in scientific workflows: An empirical analysis
doco:list of authors</p>
      <p>Daniel Garijo, Pinar Alper, Khalid Belhajjame, Oscar Corcho , Yolanda Gil ,Carole Goble
foaf:person
Ontology Engineering Group, Universidad Politécnica de Madrid, Spain</p>
      <p>School of Computer Science, University of Manchester, United Kingdom</p>
      <p>Information Sciences Institute, Department of Computer Science, University of Southern California, United States
Abstract. Workflow technology continues to play an important
role as a means for specifying and enacting
computational experiments in modern science………
scientific:hypothesis
deo:background
Acknowledgments
This research was supported by the…</p>
      <p>doco:bibliography</p>
      <p>Fig. 1. The proposed model for describing a scienti c document taking together some
of the described ontologies.
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