Presentation held at EKAW 2014. Full paper at http://link.springer.com/chapter/10.1007/978-3-319-13704-9_13

1. Ontology Design Pattern
Property Specialisation
Strategies
Karl Hammar
Jönköping University / Linköping University

2. ODP Specialisation
• Typically a Content ODP contains/is packaged
as a small reusable OWL ontology.
• Using that general/abstract ODP in a specific
use case requires specialisation.
• Often done via import and mapping of original
OWL ontology.

3. Research Question
• How are Content Ontology Design Patterns
(ODPs) used or specialised in Ontology
Engineering projects for the Semantic web, and
what are the effects of such usage?
• Motivation: to develop better understanding of
ODP usage, supporting development of
improved (guided?) tooling for such use.

4. Method Overview
1. Gather OWL ontologies that reference known
ODP namespaces.
2. Extract mapping axioms (e.g. subsumption or
equivalency mappings b/w ontology and ODP).
3. Find recurring patterns in mapping axiom
structure.

5. Understanding ODP
Specialisation
• 347 non-trivial ontologies gathered through Google Search,
LODStats, LOV, OntologyDesignPatterns.org, IKS project
• 41 ODP-using ontologies found, with 107 mapping axioms.
• 85 % of mapping axioms are one-way subsumption of
classes or properties. ODP classes/properties are nearly
always superclasses/superproperties.
• 20 ODP specialisation modules that specialise object
properties.
• Three distinct ways of specialising properties were noted.

6. Property-Oriented Strategy
• Most common way of modeling
property specialisation.
• New subproperties are
created.
• Domains and ranges of sub
properties narrower than
domains and ranges of
superproperties.
• Can be partially instantiated
(e.g., domain or range are
linked to more general term)
rdfs:domain rdfs:range
ce:Collection ce:hasMember owl:Thing
rdfs:subClassOf rdfs:subPropertyOf rdfs:subClassOf
cc:Content
Collection
cc:Content
Item
rdfs:domain rdfs:range
cc:hasContentMember

7. Class-Oriented Strategy
ir:Information
Realization
ir:Informati
rdfs:domain rdfs:range
ir:realizes onObject
wf:Weather
Forecast
wf:Weather
Information
rdfs:subClassOf
rdfs:subClassOf
ir:realizes some
wf:Weather
Information
owl:equivalentClass
ir:realizes only
wf:Weather
Information
rdfs:subClassOf
• Reuses original property;
constrains the use of that
property by class restriction
axioms.
• Restricts which (specialised)
classes that may be related via
a given property, i.e. locally
emulates domain/range.
• Not logically equivalent to
property-oriented strategy -
but can be used to solve
similar modeling problem.

8. Hybrid Strategy
• Does both: new subproperties are defined with
domains and ranges and property restrictions on
participating classes are also put in place
(possibly redundantly).

9. Specialisation Strategies
Specialisation strategy Occurrences
Property-oriented 9
Class-oriented 6
Hybrid 5

10. RQs Evolved
• To what degree are the class-oriented, property-oriented,
or hybrid property specialisation
strategies used in published ontologies?
• What are the reasoning performance effects of
specialising in accordance with the class-oriented
or property-oriented strategies?

11. Strategy Use
Specialisation
strategy
Occurrences Distribution
ODP specialisation
distribution
Property-oriented 193 78 % 45 %
Class-oriented 33 13 % 30 %
Hybrid 23 9 % 25 %

12. Strategy Effects
• Property-Oriented strategy treats properties as first-order
citizens that can be annotated and typed.
• Property-Oriented strategy possibly more intuitive for non-expert
users?
• Class-Oriented strategy makes resulting ontologies and
datasets interoperable to greater degree.
• Class-Oriented strategy causes computationally unfavorable
conditions and places ontology outside OWL2 EL.

13. Strategy Effects
Reasoning task Benchmark Reasoner PO time CO time
Consistency checking BSBM Pellet 1.274 s 1.897 s
Consistency checking BSBM HermIT 1.984 s 27.193 s
Consistency checking LUBM Pellet 8.230 s 42.887 s
Consistency checking LUBM HermIT 10.097 s 46 min
Realising individuals BSBM Pellet 2.389 s 9.482 s
Realising individuals LUBM Pellet 1.801 s 4+ hours

14. Conclusion
• Three strategies for property specialisation are
found both amongst ODPs and ontologies in
general.
• Pure Property-Oriented strategy less common
among ODP-using ontologies than among
ontologies in general.
• There may be tradeoffs between performance and
interoperability that ODP users and tooling need
be aware of.

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