Everyday Requirements for an Open Ontology Repository

1. Everyday Requirements for an Open Ontology Repository Denise Bedford Ontolog Community Panel Presentation April 3, 2008

2. Key Questions • Addressing three questions in the context of what I do each day • Everyday work context involves full ontology life cycle: • Creating and adapting ontologies • Implementing and maintaining existing ontologies • Share ontologies from time to time • Main question for me in thinking through the issues was: is there a difference between what I expect from my internal registry and repository, and what I would expect from an external one? • Are there differences based on whether we’re talking about a registry or repository?

4. Institutional vs. Community OORs • In my everyday work environment I use both registries and repositories to manage ontologies • Registry in the form of a master data store which provides basic metadata and metainformation about each source • Repositories or source systems which actually contain the ontologies • Registries can take as a baseline ISO 11179 but needs considerable extension to provide all the metainformation (fitness for use) needed to make decision to use/not use • Metainformation about the ontology is critical not just metadata • Repositories implications …. • Different architectures suited to the nature of the ontology • More important to me that the repository be suited to the ontology than that I try to force fit an ontology into a single repository structure • Application implications for accessing and using the ontology

5. OOR Requirements • Given these distinctions, purpose of an OOR would be to provide a framework for documenting and helping anyone to understand features and dimensions that should be or were considered in the design, creation, management and exchange of ontologies • Four dimensions for what I need to know about an ontology before I create it or consider using it… • Context and purpose • Content and concepts • Structures and relationships • Governance • My everyday decision for an ontology design or whether to use an existing one builds as I consider each of these dimensions

6. What I Need to Know – Context & Purpose • What kind of a domain does it represent? Topical, process oriented, personal, institutional, political, economic, research vs. application…. • Does it represent a formal or an informal knowledge domain • Is the design top down or bottom up? (users vs. intermediaries and developers?) • is it intended for human or machine use and application? • What is the intended application context – search, financial analysis, logical inference, simple classification, dynamic clustering, conceptual indexing, knowledge mapping, metadata representation??

7. What I Need to Know -- Content • Purpose and warrant -- intended audience, basic functionality supported • Type of content -- data/numbers, calculations or ratios, words, grammatical fragments, logical statements, rule expressions or engineering equations • Degree of ambiguity built into the content -- contextual sensitivity or insensitivity of the content • Representational form – • does it have a usable encoding form or specification or do I have to do a log of manual transformation? • Is the data distinct from the business rules? Can I use one without the other? • Degree of conceptualization – is it theoretical or applied?

8. What I Need to Know – Structure & Representation • What form do the relationships take? Grammatical, mathematical, logical? • How do the relationships behave – what kind are there? derivational, causal, equivalence, representational or instance, class membership only, etc. • Have the relationships been validated? Can I trust them? Fully subjective, grammatical validation only, mathematical validation, logical rigor? • How tested – is methodology exposed? • What is the encoding structure? Are there conversion programs available? • What is the business logic – is it exposed and can I review it? • Do I need to use their business logic to interpret? Can I strip it out and add my own?

9. What I Need to Know -- Governance • Does it have a formal, standard set of guiding principles which I can interpret or adapt, or is it entirely home grown and serendipitously developed? • How are the GPs enforced? Prescriptive vs. description – how reliable is the enforcement? • What is the change management process? Can I access changes? • Is it extensible or can I build upon it in its current form? • How current is the ontology? Does it represent a 1980s view and is that view still valid for the context? • Do I trust the organization or people who have built and maintained it? How much effort will I have to put into reconciling?

10. Application Value to My Work • From an ontology life cycle perspective, there are three major stages in which an OOR can provide value • Creation and deployment stage • Maintenance and management stage • Sharing or exchange stage • I would expect an OOR to provide me with information I need at any stage of the life cycle

11. Value of Community OOR • Knowledge value • current knowledge of ontologies is limited to who we know and our social networks • Open registry would have tremendous general knowledge domain value (registry) • Collaboration value • We’re working on a business model to make some of our ontologies available in a collaborative space to support shared development (Registry + repository) • Simple publish and subscribe value • Same business model can be used to make ontologies available for reuse and adaptation by others (registry + repository)

12. Advice and Suggestions • Just because ontologies are available does not mean they will be used – set the success factor at increased knowledge and participation • Start small and learn with a registry model, then incrementally build in the complexity of repositories for different types and degrees • Eventually, an OOR will be used to evaluate or characterize ontologies • Development of an OOR must go hand in hand with the metrics used to evaluate ontologies -- build the registry on attributes that will be used by people and machines to evaluate

13. Thank You! db233@georgetown.edu dbedfor3@kent.edu dbedford@utk.edu dbedford@worldbank.org