Change Management and Versioning in Ontologies


Published on

Talk at Semantic Technologies Conference 2006 (March 6-9, San Jose)

Published in: Technology, Education
  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Change Management and Versioning in Ontologies

  1. 1. Change Management and Versioning in Ontologies Baden Hughes Department of Computer Science and Software Engineering The University of Melbourne Parkville VIC 3010, Australia © 2005 Your name here The University of Melbourne Baden Hughes /
  2. 2. Agenda Definitions Ontology Change Typology of Change Practical Matters Change-Aware Tools Conclusion 2 © 2005 Your name here.
  3. 3. Definitions Ontology = specification of a conceptualisation of a knowledge domain (Gruber, 1993) OWL = OWL Lite and OWL DL, although many principles also hold for OWL-Full 3 © 2005 Your name here.
  4. 4. Ontology Change © 2005 Your name here The University of Melbourne Baden Hughes /
  5. 5. Why Ontologies Change Ontology change induced by – domain changes – adaptations to different applications – changes in conceptualization or understanding Ontologies have a general tendency to have more changes the earlier they are in their lifecycle Modularized ontologies have a general tendency to change asynchronously 5 © 2005 Your name here.
  6. 6. Real World Ontology Change: UNSPSC UN Standard Products and Service Code (UNSPSC), – “An open, global multi-sector standard for efficient, accurate classification of products and services” – Primarily targeted at e-commerce UNSPSC change history – 16 updates between 1/2001 and 9/2001 – Each update contained between 50 and 600 changes – In 7.5 months, >20% of the “standard” is changed 6 © 2005 Your name here.
  7. 7. Tracking Change: Comparison or Versioning ? Ontology versioning – mechanism to store and identify various versions of the same ontology and highlight their differences. Ontology comparison – helps knowledge managers to locate changes between different versions of an ontology If conceptual relations between different versions are constructed, it becomes possible to re-interpret the data and knowledge under different ontology versions – Semantic, rather than syntactic resolution Non-dynamic response to changes in ontologies may affect the use of these ontologies by higher level applications. – Applications need to update their logic to reference the new ontology. 7 © 2005 Your name here.
  8. 8. Typology of Change © 2005 Your name here The University of Melbourne Baden Hughes /
  9. 9. Generic Changes Change types – Non-logical change – Logical definition change – Identifier change – Addition of definitions – Deletion of definitions Extent of change – Transformation or actual change – Conceptual relation – Descriptive meta-data like date, author, and reason of the update – Valid context 9 © 2005 Your name here.
  10. 10. Example Ontology Changes (for OWL) Hierarchy – Adding a class or property – Removing a class or property – Merging two classes or properties – Splitting a class into two classes Class – Renaming a class – Changing label, comment or cardinality of a class – Changing parent – Removing parent – Adding a child – Removing a child – Adding a property to a class – Removing a property from a class 10 © 2005 Your name here.
  11. 11. Example Ontology Changes (for OWL) Properties – Renaming a property – Changing the domain – Changing the range – Changing the sub-property reference – Changing label or comment Other change types – Property characteristics – Equality or inequality – Restricted cardinality – Union or intersection 11 © 2005 Your name here.
  12. 12. Practical Matters © 2005 Your name here The University of Melbourne Baden Hughes /
  13. 13. Change Management Processes Logical that ontology changes should be handled like other types of (software) changes – Proposal, review, evaluation, implementation Distributed authoring and maintenance poses a challenge for treating ontologies this way Application level dependencies (particularly reasonings) also need to be considered as well 13 © 2005 Your name here.
  14. 14. Naming and URIs (for OWL) Naming ontologies and ontology versions – Assign a URI to the ontology and to each version of the ontology – Use a convention when constructing URIs for ontology versions and apply it consistently Naming of classes and properties – Do not use ontology version URIs to construct URIs for clases and properties – The ontology may have identified versions, but the ontology version URIs are not used to construct new class or property URIs at each version 14 © 2005 Your name here.
  15. 15. Version Metadata (for OWL) Where URIs have been allocated to the ontology and also to each ontology version, generic (DublinCore) metadata can assert formal relations • dc:isVersionOf and dc:hasVersion If the ontology version is also an formal ontology then OWL’s own versioning constructs can be used • owl:priorVersion and owl:backwardsCompatibleWith • owl:versionInfo is also possibility 15 © 2005 Your name here.
  16. 16. Deprecation Metadata (for OWL) Where a replacement has been made, generic DublinCore metadata – dcterms:replaces and dcterms:isReplacedBy – NB these are not formally asserted relations owl:DeprecatedClass and owl:DeprecatedProperty can be used to state that a class or property should no longer be used 16 © 2005 Your name here.
  17. 17. Change Logs In contrast with the open formats used for many popular ontologies (eg XML based representations), many ontology editing tools – Use proprietary formats for change logs – Document informally specified changes Many ontology editing tools only partially record changes There is no substitute for a traditional version control system in conjunction with an ontology editing environment 17 © 2005 Your name here.
  18. 18. Some Change-Aware Tools © 2005 Your name here The University of Melbourne Baden Hughes /
  19. 19. Protégé Dominant ontology editor/browser Reasonable features for ontology change management and versioning – Undo/Redo with command history – Version archiving with time-stamping and comments PROMPT plug-in for multiple ontology management • Compare, move, merge, extract Formal change logging (machine readable) 19 © 2005 Your name here.
  20. 20. OntoView Structure based comparison for ontologies Supports unique identifiers and persistence of change Differentiation at formal definition, comment, conceptualization vs explication Interactive user support Export formal translations and transformations Automated inconsistency checking 20 © 2005 Your name here.
  21. 21. SWOOP Web-based ontology browser and editor Capture and annotation mechanism for atomic ontology changes Enables exchange of changes amongst community of users Human, not machine targeted 21 © 2005 Your name here.
  22. 22. LINGOES/OntoChange Architecture for ontology management based on OntoGloss, RDF data store, change management process and a UI Formal specification of change types Formal representation of changes (delta) Rules for traversing changes Version hierarchy 22 © 2005 Your name here.
  23. 23. Others SHOE – Formal versioning and backwards compatibility PromptDIFF – Fixed-point algorithm and implementation (partially in Protégé) CONCORDIA – Retirement for concepts and concept versioning; type hierarchy impact tracing SemVersion – Structural and semantic versioning 23 © 2005 Your name here.
  24. 24. Conclusions © 2005 Your name here The University of Melbourne Baden Hughes /
  25. 25. Open Issues Is the relationship between increasing formality of expression and change impact entirely predictable? Heavy modularization of ontologies is largely inefficient in dissipating effects of changes Is developing an ontology of change is possibly an effective counter-measure to unpredicted high- impact changes ? Can we more effectively adopt methodologies for change management and versioning from software and data engineering ? Is ontology change management more a socio- technical problem rather than purely technical problem ? 25 © 2005 Your name here.
  26. 26. Parting Thoughts The state of the art in change management and versioning in ontologies is not particularly advanced Theoretical development of models for change is still continuing Tool support is emerging, but lacks cohesion around a single methodology Robust ontology-dependent application instances are difficult to achieve Change impact amelioration strategies can dissipate downstream effects of changes 26 © 2005 Your name here.
  27. 27. Key References Heflin & Hendler, 2000. Dynamic Ontologies on the Web. Proc. AAAI- 2000. Klein & Fensel, 2001. Ontology Versioning on the Semantic Web. Proc. Intl. Semantic Web Working Symp. Klein, Kiryakov, Ognyanov & Fensel, 2002. Finding and Characterizing Changes in Ontologies. Proc. 21st Intl. Conf. on Conceptual Modelling. Noy & Klein, 2003. Ontology Evolution: Not the Same as Schema Evolution. Knowledge and Information Systems 5. Noy & Musen, 2004. Ontology Versioning in an Ontology Management Framework. IEEE Intelligent Systems 19(4). Liang, Alani, Shadbolt, 2005. Change Management: The Core Task of Ontology Versioning and Evolution. Proc. PREP 2005. Liang, Alani, Shadbolt, 2005. Ontology Change Management in Protégé. Proc. AKT DTA Colloquium. Mostowfi & Fotouhi, 2005. Change in Ontology and Ontology of Change Proc. K-CAP 2005 Workshop on Ontology Management. 27 © 2005 Your name here.
  28. 28. Offline Q&A, Contact Info Baden Hughes Department of Computer Science and Software Engineering The University of Melbourne Parkville VIC 3010, Australia © 2005 Your name here The University of Melbourne Baden Hughes /