The Faceted Classi cation Scheme (FCS) ODP is a
Reengineering ODP that transforms a non-ontological resource from
the eld of Library and Information Science, also known as
Faceted Classi cation Scheme, into an ontological resource.
The ontological resource corresponds to an OWL DL model
that results from a speci c application of the Normalisation
ODP [4] [
The FCS ODP targets a speci c, very recurrent modeling issue in ontology development, subject to the vulnerability of ad-hoc modeling practices that could potentially lead to unexpected or undesirable results in ontology artifacts. The scenario consists of domain-speci c concepts that can be represented according to multiple alternative classi cation criteria. To the best of our knowledge, guidelines for the conceptualization and representation of domain-speci c concepts prone to be described based on multiple (potentially alternative) classi cation criteria, has not been explicitly considered in the context of ontology modeling for the Semantic Web.
An extended and detailed version of all the sections that follow and the rationale behind the FCS ODP is presented at length in [5].
A FCS is de ned 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 nd what they need"
[
The Norm. ODP is classi ed as a \Good Practice" pattern
in the catalog of ODPs introduced in [
The key similarity between these two conceptual models, lies in the notion of (a) facet in FCSs; and (b) module (or semantic axis) in the Norm. ODP. Both elements represent one perspective of the domain being modelled, a single characteristic of division, a single criterion of classi cation in their respective paradigm.
T DC
FCS ODP OWL Impl. :T DC owl:Class (primitive) :F aceti owl:Class (primitive) :hasF aceti owl:ObjectProperty :FiT ermj owl:Class (primitive) :FiT ermjT DC owl:Class (def.) ( ) :Specif icT DCx owl:Class (primitive) owl:Thing |-- :F aceti
|-- :FiT ermj |-- :T argetDomainConcept (or :T DC) |-- ( ) :FiT ermjT DC |-- :Specif icT DCx owl:topObjectProperty
|-- :hasF aceti
The main principle is to represent each facet as an independent module or semantic axis. Following this principle makes the application of the Norm. ODP almost straightforward. Moreover, the resultant ontology includes the representation of the multiple alternative classi cation criteria that were considered in the original FCS for the target domain concept.
Table 1 summarizes the alignment of the elements in the generic structure of both conceptual models. This alignment enables the conversion of a FCS into an OWL DL ontology by applying the Norm. ODP, where:
T DC denotes the target domain concept (or domain of discourse) of the FCS.
F aceti denotes one of the facets of the FCS.
FiT ermj denotes one of the terms of F aceti.
Itemx denotes one the items from the domain of discourse to be classi ed. Form: gel, gelpac, liquid, powder, tablet Scent: green apple, green tea, lavender, lemon, mandarin, ocean breeze, [...] Effect on Agent: aroma therapy (subdivisions: invigorating, relaxing) Special Property: antibacterial 3. PATTERN USAGE EXAMPLE
Figure 2 presents the facets and terms of a FCS example
in the domain of \Dishwashing Detergent" from [
To apply the FCS ODP, the elements in the generic
ontology structure (derived from the Norm. ODP) in Fig. 1
are populated with the facets and terms of the \Dishwashing
Detergent" FCS example in Fig. 2, according to the
alignments speci ed in Table 1. The overall normalised ontology
model obtained as a result is presented in Fig. 3. A version
of the complete normalised ontology model for the
\Dishwashing Detergent" FCS example in [
The FCS ODP considered previous work that de ned
mappings between di erent semantic models and OWL
ontologies such as the Resource Space Model (RSM) [6] and the
concept of Faceted Lightweight Classi cation Ontology [
The FCS ODP has presented an initial set of basic design guidelines to develop an OWL DL ontology model that supports the representation of multiple alternative classi cation criteria of a speci c domain concept. These guidelines provides a partial solution to potentially hazardous ad-hoc practices in the development of such ontology models, putting forward a systematic and t-for-purpose approach. 1http://purl.org/net/project/enakting/ontology/detergent fcs norm owl:Thing |-- :Agent |-- :Person |-- :Dishwasher |-- :Form |-- :Gel |-- :Gelpac |-- (... rest of terms in the facet "Form") |-- :BrandName |-- :Cascade |-- :Electrasol |-- (... rest of terms in the facet "Brand Name") |-- :Scent |-- :GreenApple |-- :GreenTea |-- (... rest of terms in the facet "Scent") |-- :EffectOnAgent |-- :AromaTherapy |-- :Invigorating |-- :Relaxing |-- :SpecialProperty
|-- :Antibacterial |-- :DishwashingDetergent (:TDC) |-- ( ) :ManualDishDetergent |-- ( ) :DishwasherDishDetergent |-- ( ) :GelDishDetergent |-- ( ) :GelpacDishDetergent |-- ( ) (... rest of subclasses for each term
in the facet "Form") |-- ( ) :CascaseDishDetergent |-- ( ) :ElectrasolDishDetergent |-- ( ) (... rest of subclasses for each term
in the facet "Brand Name") |-- ( ) :GreenAppleDishDetergent |-- ( ) :GreenTeaDishDetergent |-- ( ) (... rest of subclasses for each term
in the facet "Scent") |-- ( ) :AromaTherapyDishDetergent |-- ( ) :InvigoratingDishDetergent |-- ( ) :RelaxingDishDetergent |-- ( ) :AntibacterialDishDetergent |-- :PresidentsPersonLiquidAntibacterial |-- :PalmoliveAromaTherapyLavenderYlangYlang |-- :SpecificDishDetergent3 |-- (... rest of specific dish detergent classes
:Specif icDishDetergentx to classify) owl:topObjectProperty |-- :hasAgent |-- :hasForm |-- :hasBrand |-- :hasScent |-- :hasEffectOnAgent |-- :hasSpecialProperty ( ) denotes a de ned owl:Class. [4] A. L. Rector. Modularisation of domain ontologies implemented in description logics and related formalisms including owl. In K-CAP '03: Proceedings of the 2nd international conference on Knowledge capture, pages 121{128, New York, NY, USA, 2003. ACM. [5] B. Rodriguez-Castro, H. Glaser, and L. Carr. How to reuse a faceted classi cation and put it on the semantic web. In The 9th International Semantic Web
Conference (ISWC), June 2010. [6] H. Zhuge, Y. Xing, and P. Shi. Resource space model, owl and database: Mapping and integration. ACM Trans. Internet Technol., 8(4):1{31, 2008.