| GeneralDescription
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A FCS is defined as: "a set of mutually ex … A FCS is defined as: "a set of mutually exclusive and jointly exhaustive categories, each made by isolating one perspective on the items (a facet), that combine to completely describe all the objects in question, and which users can use, by searching and browsing, to find what they need" [[Community:References/How_to_Make_a_Faceted_Classification_and_Put_It_On_the_Web_3|(Denton, 2003)]].
The following notation is introduced to refer to the elements of a generic FCS in the figure below:
* ''Target Domain Concept'' (''TDC'') denotes the domain of discourse. The domain-specific concept targeted by the FCS.
* ''Facet_i'' denotes one of the facets of the FCS.
* ''F_iTerm_j'' denotes one of the terms of ''Facet_i''.
* ''Item_x'' denotes one the items from the domain of discourse (''TDC'') to be classified. n of discourse (''TDC'') to be classified.,
Generic structure of the [[Submissions:Nor … Generic structure of the [[Submissions:Normalization|Normalization]] ODP used to represent a Faceted Classification Scheme (FCS).
[[Image:NormalizationGenericStructure1.png|center|frame|The symbol (≡) denotes an OWL defined class.]]
The figure below represents a further generalization of the [[Submissions:Normalization|Normalization]] ODP and introduces the following notation:
* '':TDC'' denotes a primitive class representing the domain concept being normalized.
* '':Module_i'' denotes a primitive class that represents one of the modules.
* '':M_iClass_j'' denotes a primitive class that represents a subset of the module class '':Module_i''.
* '':hasModule_i'' denotes an object property that links every module '':Module_i'' to the different subclasses of the target domain concept '':M_iClass_jTDC'' and '':SpecificTDC_x''.
* '':M_iClass_jTDC'' denotes a defined class that represents a subset of the target domain concept class '':TDC''. Every class '':M_iClass_jTDC'' is defined based on its relationship to the single corresponding class '':M_iClass_j'' that it is derived from.
* '':SpecificTDC_x'' denotes a primitive class that represents a subset of the target domain concept class '':TDC'' and an entity from the domain to be classified. Every class '':SpecificTDC_x'' is described based on its relationship to various classes '':M_iClass_j'' from potentially different modules. As a consequence of this relationship, the classes '':SpecificTDC_x'' could introduce the polyhierarchy scenarios in the ontology model that the [[Submissions:Normalization|Normalization]] ODP aims to manage and untangle.
The implementation of a generic defined class '':M_iClass_jTDC'' is given as follows:
'':M_iClass_jTDC'' rdf:type owl:Class ;
rdfs:subClassOf '':TDC'' ;
owl:equivalentClass [ rdf:type owl:Restriction ;
owl:onProperty '':hasModule_i'' ;
owl:someValuesFrom '':M_iClass_j''
] .
The implementation of a generic class '':SpecificTDC_x'' is given as follows:
'':SpecificTDC_x'' rdf:type owl:Class ;
rdfs:subClassOf '':TDC'' ,
[ rdf:type owl:Restriction ;
owl:onProperty '':hasModule_i'' ;
owl:someValuesFrom '':M_iClass_j''
] ,
[ ... rest of existential restrictions on property '':hasModule_i''
for every class '':M_iClass_j'' that participates
in the description of '':SpecificTDC_x''
] .
This implementation of the classes '':M_iClass_jTDC'' and '':SpecificTDC_x'' respectively, enable a reasoner to infer and maintain the subsumption relations between a given class '':SpecificTDC_x'' and the various classes '':M_iClass_jTDC'' that it is related to. '':M_iClass_jTDC'' that it is related to.,
Mapping between the elements in the generi … Mapping between the elements in the generic structure of a Faceted Classification Scheme and the [[Submissions:Normalization|Normalization]] ODP.
The table below summarizes the alignment of the elements in the generic structure of both conceptual models. This alignment enables the conversion from a FCS to an OWL DL ontology by applying the [[Submissions:Normalization|Normalization]] ODP:
* The first column (leftmost), contains the elements of a generic FCS as introduced in section '''Non-Ontological Resource''' above.
* The second column contains the elements of the [[Submissions:Normalization|Normalization]] ODP generic structure
as introduced in section '''Ontology''' above.
* The third column represents the selected OWL notation for the elements of a generic FCS in the context of the [[Submissions:Normalization|Normalization]] ODP generic structure.
* The forth column (rightmost), indicates the OWL implementation chosen for every element. The selection complies with the requirements of the normalization mechanism.
[[Image:MappingFCSNormalizationODP.png|center]]
Based on the principle of representating each facet of a FCS as a module of the [[Submissions:Normalization|Normalization]] ODP, the underlying ideas behind the mappings in the figure(table) above can be outlined as follows:
* The target domain concept ''TDC'' represents the domain of discourse of both a FCS and the [[Submissions:Normalization|Normalization]] ODP. The primitive class '':TDC'' fulfills that role in the normalized ontology.
* A facet ''Facet_i'' from a generic FCS corresponds to a module '':Module_i'' in the [[Submissions:Normalization|Normalization]] ODP, therefore it becomes a primitive class '':Facet_i'' in the normalized ontology model.
* A facet ''Facet_i'' from a FCS also becomes an object property '':hasFacet_i'' in the normalized ontology, given that for every module '':Module_i'' in the [[Submissions:Normalization|Normalization]] ODP, there is an object property '':has_Module_i''.
* From the relationship between facet and module, it follows that a facet term ''F_iTerm_j'' from a FCS maps to a module subclass '':M_iClass_j'' from the [[Submissions:Normalization|Normalization]] ODP. Both elements represents the same notion in their respective conceptual models. A subvidision, a refinement of the facet or module that they complement respectively. Therefore, a facet term ''F_iTerm_j'' from a FCS becomes a primitive class '':F_iTerm_j'' in the normalized ontology.
* A facet term ''F_iTerm_j'' from a FCS also produces a defined class '':F_iTerm_jTDC'' in the normalized ontology, given that for every primitive class '':M_iClass_j'' in the [[Submissions:Normalization|Normalization]] ODP, there is a corresponding defined class '':M_iClass_jTDC''.
* Every item ''Item_x'' to be classified in the FCS aligns to a class '':Specific_x'' that is automatically classified by a reasoner in the [[Submissions:Normalization|Normalization]] ODP. Therefore, every element ''Item_x'' is represented as a primitive class '':SpecificTDC_x'' in the normalized ontology. pecificTDC_x'' in the normalized ontology.,
To create an ontology model to represent an existing Faceted Classification Scheme for a specific domain concept.,
The figure below recaps the final FCS deve … The figure below recaps the final FCS developed for the "Dishwashing Detergent" domain example in [[Community:References/How_to_Make_a_Faceted_Classification_and_Put_It_On_the_Web_3|(Denton, 2003)]](§ 2.4). The elements of the schema fit into the generic structure of a FCS presented in section '''Non-Ontological Resource''' earlier, where:
* The ''TDC'' element is populated with the domain "Dishwashing Detergent".
* ''Facet_i'' elements are populated with the facets: "Agent", "Form", "Brand Name", "Scent", "Effect On Agent", and "Special Property".
* ''F_iTerm_j'' elements are populated with the terms or foci listed below (grouped by facet):
** Agent: dishwasher, person.
** Form: gel, gelpac, liquid, powder, tablet.
** Brand Name: Cascade, Electrasol, Ivory, No Name, Palmolive, President's Choice, Sunlight.
** Scent: green apple, green tea, lavender, lemon, mandarin, ocean breeze, orange blossom, orchard fresh, passion flower, ruby red grapefruit, ylang ylang.
** Effect on Agent: aroma therapy (subdivisions: invigorating, relaxing).
** Special Property: antibacterial.
* ''Item_x'' elements are populated in this case with two example items to classify:
** "President's Choice Antibacterial Hand Soap and Dishwashing Liquid".
** "Palmolive Aroma Therapy, Lavender and Ylang Ylang".
To illustrate the representation of a specific dishwashing detergent, let us reuse the two classification examples presented in [[Community:References/How_to_Make_a_Faceted_Classification_and_Put_It_On_the_Web_3|(Denton, 2003)]](§ 2.4). Applying the "Dishwashing Detergent" FCS developed in the cited reference, the item "President's Choice Antibacterial Hand Soap and Dishwashing Liquid" is classified as follows:
* Agent: person
* Form: liquid
* Brand Name: President's Choice
* Scent: (none)
* Effect on Agent: (none)
* Special Property: antibacterial
The item "Palmolive Aroma Therapy, Lavender and Ylang Ylang," is classified as:
* Agent: person
* Form: liquid
* Brand Name: Palmolive
* Scent: lavender, ylang ylang
* Effect on Agent: aroma therapy
* Special Property: (none) : aroma therapy
* Special Property: (none),
OWL representation of the "Dishwashing Det … OWL representation of the "Dishwashing Detergent" domain concept Faceted Classification Scheme applying the Normalization ODP.
[[Image:FacetedClassificationSchemeOntoExObjProp.png|center|frame|List of object properties.]]
The symbol (≡) denotes an OWL defined class. e symbol (≡) denotes an OWL defined class.,
According to the guidelines derived from t … According to the guidelines derived from the table in section '''Process''' above and the implementation of a class '':SpecificTDC_x'' given in section '''Ontology''' above, the description of the example detergent "President's Choice Antibacterial Hand Soap & Dishwashing Liquid" in the normalized ontology can be stated as follows:
:PresidentsPersonLiquidAntibacterial
rdf:type owl:Class ;
rdfs:subClassOf :DishDetergent ,
[ rdf:type owl:Restriction ;
owl:onProperty :hasAgent ;
owl:someValuesFrom :Person
] ,
[ rdf:type owl:Restriction ;
owl:onProperty :hasForm ;
owl:someValuesFrom :Liquid
] ,
[ rdf:type owl:Restriction ;
owl:onProperty :hasBrandName ;
owl:someValuesFrom :PresidentsChoice
] ,
[ rdf:type owl:Restriction ;
owl:onProperty :hasSpecialProperty ;
owl:someValuesFrom :Antibacterial
] .
The description of the example detergent "Palmolive Aroma Therapy, Lavender and Ylang Ylang," would be:
:PalmoliveAromaTherapyLavenderYlangYlang
rdf:type owl:Class ;
rdfs:subClassOf :DishDetergent ,
[ rdf:type owl:Restriction ;
owl:onProperty :hasAgent ;
owl:someValuesFrom :Person
] ,
[ rdf:type owl:Restriction ;
owl:onProperty :hasForm ;
owl:someValuesFrom :Liquid
] ,
[ rdf:type owl:Restriction ;
owl:onProperty :hasBrandName ;
owl:someValuesFrom :Palmolive
] ,
[ rdf:type owl:Restriction ;
owl:onProperty :hasScent ;
owl:someValuesFrom :Lavender
] ,
[ rdf:type owl:Restriction ;
owl:onProperty :hasScent ;
owl:someValuesFrom :YlangYlang
] ,
[ rdf:type owl:Restriction ;
owl:onProperty :hasEffectOnAgent ;
owl:someValuesFrom :AromaTherapy
] . rom :AromaTherapy
] .
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