Methods for Ontology Design Patterns reuse

1

Methods for ODP reuse

Valentina Presutti

Semantic Technology Laboratory (STLab), ISTC-CNRRome/Catania, Italy

17/10/2016, Kobe, Japan

ODP for Linked Data Publishing @ ISWC 2016

http://www.slideshare.net/vpresutti/methods-for-ontology-design-patterns-reuse

• Questions we will try to answer

• Background on ontology reuse

• Classification of reuse models

• Impact of reuse models

• Reuse models with their advantages and disadvantages

• Conclusion towards working examples

Outline

What is the best practice for ontology reuse?

Is it fine to use external ontology entities to model my local entities?

Should I import the ontologies that I reuse?

What if I only need a part of an ontology?

What if an external ontology that I reused, changes?

Questions we will try to answer

Ontology reuse is a recommended practice (see e.g. [Burleson et al., 2014], [Bizer et al., 2009])

reuse of standard vocabularies

linked data principles

It favors semantic interoperability [Simperl, 2009]

knowledge reuse is a key success factor for the Semantic Web

reusability is an intrinsic property of ontologies

Ontology Design Patterns (ODP) [Gangemi, 2005]

they make reuse easier, as they isolate specific requirements

Ontology reuse

[d’Aquin and Noy, 2012]: how to choose ontology libraries and current open issues for ontology library developers (many are still open)

[Suárez-Figueroa et al., 2011]: methodological guidelines for ontology engineering. As for reuse it identifies two main scenarios and lists the main activities that characterise them: reuse of ontologies as they are and reuse by alignment. ODP reuse is also considered but the possible process is not detailed in terms of activities

[Fernández-López et al, 2011]: guidelines on how to identify parts of ontologies to be reused

[Schaible et al, 2014]: survey on vocabulary reuse strategies in linked data. It shows that popularity of vocabulary is one of the most used criteria for reuse and that the focus is at terminology reuse

This tutorial is mainly based on [Presutti et al, 2016], [Lodi et al, 2016], and [Hammar and Presutti, 2016] which focus on ontology design patterns reuse for linked open data publishing

Literature on ontology reuse

Non-linear evolution of ontology design

Diversity of modelling requirements

Availability of existing ontologies

Sustainability within organisations

Trends

Personal taste of ontology designers

No standard for reuse

Reuse models

• Type of reused ontologies

• Type of reused ontology fragments

• Amount of reused axioms

• Alignment policy

Classification of reuse models

Reuse of foundational [Gangemi et al, 2003] or top-level ontologies [DBpedia Ontology]

Specialising DOLCE or the DBpedia Ontology

Modelling events and participation in them

Cultural institutes involved in an exhibition

Type of reused ontologies

Reuse of Ontology Design Patterns

Participation ODP to model event participation


Reuse of domain ontologies

Reusing the Event Ontology [Raimond and Abdallah, 2007]

Music events


Reuse of individual entities (classes, relations, individuals)

dolce:hasParticipant, dbpedia-owl:Event

Reuse of “groups” of entities (modules, ODP, or arbitrary fragments)

Participation ODP

dolce:hasParticipant and all its relevantly related entities,

e.g. dolce:Object, dolce:Event, etc.

The whole Event Ontology

Type of reused ontology fragments

Reuse of ontologies including all their axioms

the whole DOLCE, the whole Event Ontology

Reuse only of axioms in a given neighborhood of a specific entity

referred to as ontology module

dolce:hasParticipant + entities and axioms within a certain graph distance

Only reuse individual entities’ URIs with no axioms

Amount of reused axioms

Direct reuse

entities and axioms delegated to an external ontology

dolce:Event as type of ontology individuals in my ontology

Indirect or template-based reuse

define my own entities and align them to external ontologies

myont:CulturalEvent rdfs:subClassOf dolce:Event

XDP (WebProtégé plugin) offers tool support (afternoon session)

Alignment policy

Reusing an ontology, ontology fragment, or ontology entity does not imply to use <owl:import>, nevertheless

In order to assess semantic coherence and consistency of the resulting ontology wrt its requirements, one needs to <owl:import> the reused ontologies, at least for the time needed to perform these tasks

<owl:import>

The only shared characteristic among all these practices is that entities are reused with their original logical type

If Ol reuses Or then

e rdfs:type owl:Class and e ∈ Or

implies

f rdfs:type owl:Class and e ∈ Ol

e ≡ | ⊆ f

Reuse models

All these models can be mixed in a same ontology project, or different projects from the same organisation may apply different strategies

There is not “the best for all situations” model

Regardless the trend or taste, the type of reuse impacts on the developed ontology project

The choice of reuse model must be done according to the ontology project’s contextual requirements

Reuse models

Ontology semantics

maximal commitment: when we reuse a whole ontology with all its axioms

minimal commitment: when we indirectly reuse an individual entity without importing its related axioms

semantics is safer and more complete in case of maximal reuse

Impact of reuse models

Sustainability and usability

maximal reuse may mean less usability

useless or undesired entities and axioms

strong dependency on external resources

risk of incoherence wrt original requirements after external changes


Interoperability

minimal reuse may simplify interoperability

the less constraints given by axioms the simpler interoperability


The focus on quality of semantics pushes towards maximal reuse, while the focus on interoperability and sustainability/usability pushestowards minimal reuse

The vision of the designer, the scope of the project, the type of project and the nature of data that we deal with are at the basisof the choice of a reuse model

The goal is to maximise the quality of semantics withoutnegatively impact on usability, sustainability, and interoperability


Direct reuse of individual entitiesEXT

ONT

LOC

ONT

Advantages Disadvantages

Semantic ambiguityDifficulty in verifying consistencyStrong external dependency Risk of instability Possible sustainability issues

Linked data praxisReuse of shared terminologyGood if one wants to complywith and follow evolution of standards

Direct reuse of ODP

23


Dependency on external moduleMitigated risk of instability

Stability and sustainabilityModularityInteroperabilityODP are unlikely to changeEasy to re-design in case of changes

loc:Person

loc:organises

Indirect reuse of modules

24


Possible heterogeneity in module identificationDifficulty in providing formal specification of external moduleEffort for replicating the module implementation

Dependency on external changes is limited to alignment axiomsEasier re-design for fixing issues due to external changesStability and sustainabilityModularity and Interoperability

Alignmentaxioms

Indirect reuse of ODP

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Effort for replicating the ODP implementation

Dependency on external changes is limited to alignment axiomsEasier re-design for fixing issues due to external changesStability and sustainabilityModularity and interoperability

Alignmentaxioms

Summarising tableDirect reuse Indirect reuse

Individual entities

• Dependency on standards, if required

• LD praxis• Shared vocabulary• Less effort in design

• Semantics ambiguity• Difficult to verify

consistency/coherence• Strong external

dependency • Risk of instability • Possible sustainability

issues

• Dependency on standards• LD principles• Shared vocabulary• Easier to fix possible issues

due to external changes

• Semantics ambiguity• Indirect dependency from

external resources• More sustainable

Module

• Less effort in design• Clearer semantics

• Strong dependency on external resources

• Possible heterogeneity in module identification

• Difficulty in providing formal specification of external module

• Hard to fix possible issues due to external changes

• Limited dependency on external changes (only alignment axioms)

• Easier re-design for fixing issues due to external changes

• Stability and sustainability• Modularity and

Interoperability

• Possible heterogeneity in module identification

• Difficulty in providing formal specification of external module

• Effort for replicating the module implementation

ODP

• Reuse of design good practices


interoperability• ODP are unlikely to

change• Easy to re-design in case

of changes

• Dependency on external module

• Mitigated risk of instability

• Dependency on external changes is limited to alignment axioms

• Easier re-design for fixing issues due to external changes


interoperability

• Effort for replicating the ODP implementation

The second part of the morning session (Pascal Hitzler and Giorgia Lodi) is about use case scenarios

both academic and real world scenarios will be discussed and different reuse models applied

The afternoon (Karl Hammar) will be dedicated to a practical session where you will apply ontology reuse with some tools support (XDP, WebProtégé plugin)

Working examples

• Ontology reuse is a key factor for the success of Semantic Web technologies

• There is no “one fits all” solution

• Tradeoff between semantic ambiguity, usability, sustainability and interoperability, is the goal

• The stronger the commitment the safer and more complete the semantics, the lower the usability/sustainability and interoperability

• Different reuse models with their advantages and disadvantages

Conclusion

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Stupid questions are only those that are not asked (Prof. Paolo Ciancarini)

[Bizer et al., 2009] Christian Bizer, Tom Heath, Tim Berners-Lee:Linked Data - The Story So Far. Int. J. Semantic Web Inf. Syst. 5(3): 1-22 (2009)

[Burleson et al., 2014] Linked Data Platform Best Practices and Guidelines. W3C Working Group Note 28 August 2014 https://www.w3.org/TR/ld-bp/

[Simperl, 2009] Elena Paslaru Bontas Simperl: Reusing ontologies on the Semantic Web: A feasibility study. Data Knowl. Eng. 68(10): 905-925 (2009)

[Gangemi, 2005] Aldo Gangemi: Ontology Design Patterns for Semantic Web Content. International Semantic Web Conference 2005: 262-276

[Gangemi et al. 2003] Aldo Gangemi, Nicola Guarino, Claudio Masolo, Alessandro Oltramari: Sweetening WORDNET with DOLCE. AI Magazine 24(3): 13-24 (2003)[d’Aquin and Noy, 2012]

[DBpedia Ontology] The DBpedia Ontology: http://wiki.dbpedia.org/services-resources/ontology

[Raimond and Abdallah, 2007] The event ontology. Technical report, 2007.

References

[Suárez-Figueroa et al., 2011] Mari Carmen Suárez-Figueroa, Asunción Gómez-Pérez, Mariano Fernández-López: The NeOn Methodology for Ontology Engineering. Ontology Engineering in a Networked World 2012: 9-34

[Fernández-López et al, 2011] Mariano Fernández-López, Mari Carmen Suárez-Figueroa, Asunción Gómez-Pérez: Ontology Development by Reuse. Ontology Engineering in a Networked World 2012: 147-170

[Schaible et al, 2014] Johann Schaible, Thomas Gottron, Ansgar Scherp: Survey on Common Strategies of Vocabulary Reuse in Linked Open Data Modeling. ESWC 2014: 457-472

[Presutti et al, 2016] Valentina Presutti, Giorgia Lodi, Andrea Giovanni Nuzzolese, Aldo Gangemi, Silvio Peroni and Luigi Asprino: "The role of Ontology Design Patterns in Linked Data projects”. ER 2016.

[Lodi et al, 2016] Semantics for Cultural Heritage Valorisation. Giorgia Lodi, Valentina Presutti, Luigi Asprino, Andrea Nuzzolese, Diego Reforgiato, Aldo Gangemi, AnnaritaOrsini, Chiara Veninata. Springer, Data Analytics in Digital Humanities, 2016

[Hammar and Presutti, 2016] Karl Hammar and Valentina Presutti - Template-Based Content ODP Instantiation. In WOP 2016. IOS Press

References