Submissions:Literal Reification

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Current revision ID: 10190

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General description

Name: Literal Reification
Submitted by: AldoGangemi, SilvioPeroni, FabioVitali
Also Known As:
Intent: This pattern promotes any literal as “first class object” in OWL by reifying it as a proper individual of the class litre:Literal.


Competency Questions:
  • What is the context in which entities refer to a particular literal value?
  • What is the meaning of a particular value considering the context in which it is used?
Solution description: Literals are reified in proper ontological individual (belonging to the class 'Literal'), expressing the literal value they refer to through a data property. This reification allows to use each 'reified literal' as subject or object of assertions.
Reusable OWL Building Block: (1098)
Consequences: This pattern allows to specify different contexts and/or meanings to a particular literal value.
Scenarios: Modelling domains concerning descriptive tags, in which each tag may have more than one meaning depending on the context in which it is used. Extending quickly the capabilities of a model by adding the possibility to make assertions on values, previously referred through data properties, without modifying it.
Known Uses:
Web References:
Other References:
Examples (OWL files):
Extracted From:
Reengineered From:
Has Components:
Specialization Of:
Related CPs:


The Literal Reification Content OP locally defines the following ontology elements:

Literal page
hasSameLiteralValueAs page
hasLiteral page
isLiteralOf page
hasLiteralValue page

Additional information


Scenarios about Literal Reification
  • Used frequently in the Web 2.0, descriptive tags such as the ones used in folksonomies are keywords (e.g., strings) assigned to a particular resource, such as a web document, with the intent to describe it. Just like words in any natural language, tags may have different meanings depending on the context in which they are used. For instance, the word “Paris” may be either a name of a city or a first name of a person. Here, it is clear that the act of tagging with “Paris” both the Wikipedia pages about the Eiffel Tower and the one about Paris Hilton hides two different intents: in the former case, “Paris” denotes the city in which the tower stands; in the latter case, “Paris” denotes a particular person, i.e., Paris Hilton. Using the literal reification pattern it is possible to express descriptive tags as first class objects in OWL, by considering them as proper individuals of the class litre:Literal. Different individuals may thus represent different meanings even if their literal values are identical. >>>
  • NameHistory3.0 is a (fictional) institution that keeps track of all the names of people, and stores them as an ABox of the FOAF ontology. In particular, each person is stored as an individual of the class foaf:Person with a specific first name (data property foaf:givenName) and family name (data property foaf:familyName). On 24/09/2010, Bruce Wayne formally applied for changing his first name to Jack. Since NameHistory3.0 has to keep track of everything concerning names of people, on that date “Jack” was added as Mr. Wayne's first name. It was then that NameHistory3.0 noticed that, without any additional information, it is not possible to know which of the two first names are legally valid at any given point in time. A solution to that scenario, which avoids any modification of the ontology model and consequently of the entire triple store (operation that is obviously time-consuming and error-prone), is to use the literal reification pattern in combination with the new expressivity for punning in OWL 2. Through them, it is possible to define a literal individual as also belonging to the class foaf:givenName – that is actually defined as a data property, but may be additionally be meta-modelled as a class. We can now associate a particular time interval to each literal, so as to represent when the literal itself, i.e., the given name, is legally valid. >>>


Reviews about Literal Reification
Review article Posted on About revision (current is 10190)
OlafNoppens about Literal Reification 245545616 September 2010 1006210,062
MariCarmenSuarezFigueroa about Literal Reification 245545717 September 2010 1011010,110
EnricoMotta about Literal Reification 245545919 September 2010 1011010,110

This revision (revision ID 10190) takes in account the reviews: none

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