The **_Citation Counting and Context Characterization Ontology (C4O)_** allows the characterization of bibliographic citations in terms of their number and their context.
Besides defining reference lists and bibliographic references in a machine-readable form, it is also useful to describe how these references are used in the citing paper.
In particular, we would need entities that describe all the items introduced in the situation where a document - i.e., the paper 'Intertextual semantics: a semantics for information design' - cites another - i.e., 'Towards a semantics for XML markup'). Those entities include:
* in-text reference pointers within the citing paper;
* links to the bibliographic references denoted by in-text reference pointers;
* how much a particular document is locally cited by the citing document – i.e., the total number of in-text reference pointers within the citing paper denoting the same bibliographic reference; how much an article is globally cited (according to particular bibliographic citation service, e.g., Google Scholar);
* the contexts involved in a citation – i.e., the part of the citing article containing a particular in-text reference pointer and the part of the cited article that is relevant to such citation.
C4O has been developed to allow the description of the above entities.
This ontology extends [BiRO](http://purl.org/spar/biro) in order to enable the characterisation of bibliographic citations in terms of their presence in an article by means of the following classes:
* class `c4o:InTextReferencePointer ` - an in-text reference pointer is a textual device denoting (`c4o:denotes `) a single bibliographic reference that is embedded in the text of a document within the context of a particular sentence;
* class `c4o:InTextReferencePointerList` - a list containing (through the chain `co:item` and `co:itemContent`) only in-text reference pointers denoting the specific bibliographic references to which the list pertains (`c4o:pertains`). Such a list cannot contain more than one item containing the same in-text reference pointer;
* class `c4o:SingleReferencePointerList ` - defined as subclass of `c4o:InTextReferencePointerList`, it is an in-text reference pointer list that pertains to exactly one bibliographic reference;
* class `c4o:SingleLocationPointerList ` - defined as subclass of `c4o:InTextReferencePointerList`, it is an in-text reference pointer list that pertains to all the in-text reference pointers to two or more references occurring at a single location in the text of the citing work;
* class `c4o:GlobalCitationCount` - the number of times a work has been cited globally (`c4o:hasGlobalCountValue`), as determined from a particular bibliographic information source (`c4o:hasGlobalCountSource`) on a particular date (`c4o:hasGlobalCountDate`).
In addition, C4O provides the ontological structures which allow one to record the number of in-text citations (`c4o:hasInTextCitationFrequency`) i.e., the number of in-text reference pointers to a single reference in the reference list of the citing article.
Moreover, C4O enables ontological descriptions of the context where an in-text reference pointer appears in the citing document, and allows one to relate that context to relevant textual passages in the cited document.
## Examples of use
In the following subsections, we introduce some examples to showcase how to use C4O.
The prefixes that are used in all the examples provided below are defined as follows:
@prefix : <http://www.sparontologies.net/example/> .
@prefix biro: <http://purl.org/spar/biro/> .
@prefix c4o: <http://purl.org/spar/biro/> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix doco: <http://purl.org/spar/doco/> .
@prefix frbr: <http://purl.org/vocab/frbr/core#> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
### Describing citation contexts
In a particular sentence of the paper entitled 'Intertextual semantics: A semantics for information design' there is a citation to the paper 'Towards a semantics for XML markup' made through a in-text reference pointer to a specific bibliographic reference.
C4O enables ontological descriptions of the citation context where an in-text reference pointer appears in the citing document, and allows one to relate that context to relevant textual passages in the cited document.
<http://dx.doi.org/10.1002/asi.21134>
frbr:part :in-text-renear02 , :renear02 .
:in-text-renear02 a c4o:InTextReferencePointer ;
c4o:denotes :renear02 ;
c4o:hasContext :citation-sentence .
:renear02 a biro:BibliographicReference ;
dcterms:bibliographicCitation
'Renear, A., Dubin, D. & Sperberg-McQueen, C.M. (2002).
Towards a semantics for XML markup. In E. Mudson (Chair),
Proceedings of the ACM Symposium on Document Engineering,
(pp. 119-126). New York: ACM Press.' ;
biro:references <http://dx.doi.org/10.1145/585058.585081> .
:citation-sentence a doco:Sentence ;
c4o:hasContent
'Renear, Dubin, and Sperberg-McQueen (2002, pp. 121-122)
proposed a formal semantic approach for structured documents.' .
<http://dx.doi.org/10.1145/585058.585081>
frbr:part :cited-sentence .
:cited-sentence a doco:Sentence ;
c4o:hasContent
'Markup semantics are modeled computationally by applying
knowledge representation technologies to the problem of making
those structures, relationships, and properties explicit.' ;
c4o:isRelevantTo :citation-sentence .
### Keeping track of global citation count
C4O allows one to record the number of citations a cited entity has received globally (`c4o:hasGlobalCitationCount`), as determined by a bibliographic information resource (`c4o:hasGlobalCountSource`) such as Google Scholar, Scopus or Web of Knowledge on a particular date (`c4o:hasGlobalCountDate`).
For instance we can write a set of assertions according to C4O that describe how many times the reference - contained in the paper 'Intertextual semantics: A semantics for information design' and referring to the paper 'Towards a semantics for XML markup' - is used within the citing article and how much the cited article is globally cited according to Google Scholar.
<http://dx.doi.org/10.1002/asi.21134>
frbr:part :renear02 .
:renear02 a biro:BibliographicReference ;
dcterms:bibliographicCitation
'Renear, A., Dubin, D. & Sperberg-McQueen, C.M. (2002).
Towards a semantics for XML markup. In E. Mudson (Chair),
Proceedings of the ACM Symposium on Document Engineering,
(pp. 119-126). New York: ACM Press.' ;
biro:references <http://dx.doi.org/10.1145/585058.585081> ;
c4o:hasInTextCitationFrequency "1"^^xsd:nonNegativeInteger .
<http://dx.doi.org/10.1145/585058.585081>
c4o:hasGlobalCitationFrequency :g-citation-2014-03-17 .
:g-citation-2014-03-17 a c4o:GlobalCitationCount ;
c4o:hasGlobalCountDate '2014-03-17'^^xsd:date ;
c4o:hasGlobalCountSource :google-scholar ;
c4o:hasGlobalCountValue '5'^^xsd:nonNegativeInteger .
:google-scholar a c4o:BibliographicInformationSource ;
foaf:homepage <http://scholar.google.com> .
## Competency Questions
BiRO can be used for answering several questions related to bibliographic records and references.
In the following subsections, some of them are introduced together with their respective SPARQL queries.
The prefixes that are used in all the SPARQL queries provided below are defined as follows:
PREFIX biro: <http://purl.org/spar/biro/>
PREFIX co: <http://purl.org/co/>
PREFIX dcterms: <http://purl.org/dc/terms/>
PREFIX frbr: <http://purl.org/vocab/frbr/core#>>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX literal: <http://www.essepuntato.it/2010/06/literalreification/>
### CQ1
Which bibliographic references and citation contexts are associated with an in-text reference pointer?
SELECT ?inTextPointer ?reference ?context ?contextContent
WHERE {
?inTextPointer a c4o:InTextReferencePointer ;
c4o:denotes ?reference ;
c4o:hasContext ?context .
OPTIONAL { ?context c4o:hasContent ?contextContent . }
}
### CQ2
Which textual passages in a cited document are relevant to a citing context?
SELECT ?citingContext ?citingContent ?citedPassage ?citedContent
WHERE {
?citedPassage c4o:isRelevantTo ?citingContext .
OPTIONAL { ?citingContext c4o:hasContent ?citingContent . }
OPTIONAL { ?citedPassage c4o:hasContent ?citedContent . }
}
### CQ3
What is the in-text citation frequency of a bibliographic reference within a citing document?
SELECT ?reference ?frequency ?citedWork
WHERE {
?reference a biro:BibliographicReference ;
c4o:hasInTextCitationFrequency ?frequency .
OPTIONAL { ?reference biro:references ?citedWork . }
}
### CQ4
What is the global citation count of a document, including the source and measurement date?
SELECT ?document ?citationCount ?countValue ?source ?date
WHERE {
?document c4o:hasGlobalCitationFrequency ?citationCount .
?citationCount a c4o:GlobalCitationCount ;
c4o:hasGlobalCountValue ?countValue ;
c4o:hasGlobalCountSource ?source ;
c4o:hasGlobalCountDate ?date .
}
### CQ5
What information sources are used to track global citation counts, along with their homepages?
SELECT ?source ?homepage
WHERE {
?source a c4o:BibliographicInformationSource .
OPTIONAL { ?source foaf:homepage ?homepage . }
}