1. http://www.ontopia.net/© 2006 Ontopia AS1 Towards an Ontology Design Methodology Initial work Lars Marius Garshol CTO, Ontopia TMRA 2006 2006-10-11

2. http://www.ontopia.net/© 2006 Ontopia AS2 Agenda Background –why this is important –what it includes The process –some background –roles –steps The guidelines –examples Conclusion –further work

3. http://www.ontopia.net/© 2006 Ontopia AS3 Background Why this is important What it includes

4. http://www.ontopia.net/© 2006 Ontopia AS4 The ontology challenge For many customers, creating the ontology is the biggest hurdle –it’s something new to them, and they don’t know how to approach it –the technology is new, and so most consultants are not familiar with it –this makes the process of creating the ontology seem very intimidating –it also means that the costs and challenges are unknown Successfully developing an ontology is non-trivial –it can be politically challenging –the ontology interacts with every other part of the project... –ontology modelling requires analytical skill –the ontology is constrained by economical and technical considerations

5. http://www.ontopia.net/© 2006 Ontopia AS5 The methodology: vision A defined process –roles involved in the process –a defined series of steps to follow A set of modelling guidelines –essentially heuristics for the correct use of the constructs in Topic Maps A pattern library –common solutions to common problems A base ontology –PSIs for common concepts like “person”, “description”,... In the paper

6. http://www.ontopia.net/© 2006 Ontopia AS6 Scope There are two general classes of applications –information retrieval-type applications portals, library systems, publishing solutions, KM solutions,... –“traditional” applications CRM systems, product configuration applications, business process modelling,... Ontology design is different for these two applications –in “traditional” applications the domain is already well-understood the needs of the end-users are well-understood –none of this applies to information retrieval applications Methodology focuses on information retrieval applications –process especially –guidelines are general

7. http://www.ontopia.net/© 2006 Ontopia AS7 The process Background Roles Steps

8. http://www.ontopia.net/© 2006 Ontopia AS8 Simplified process view Vision Lacking source data Can’t analyse domain Lack of project consensus

9. http://www.ontopia.net/© 2006 Ontopia AS9 The process exists to handle these challenges Source data gap or analysis gap –make sure you discover the gap in time –make sure you can find ways to plug it, or work around it Project consensus –including the right people in the right way at the right time builds consensus –it also ensures people know what they need to know Manage dependencies –keep track of what depends on the ontology

10. http://www.ontopia.net/© 2006 Ontopia AS10 Roles Project manager –runs the project Developers –write the code System owners –make the decisions regarding the project Data source owners –manage systems which provide data to the new system –usually not part of the project End-user –user of the final system Ontology modeller –person responsible for ontology Editors –people responsible for data in the system Authors –people who write the content in the system Domain expert –someone with knowledge of the domain

11. http://www.ontopia.net/© 2006 Ontopia AS11 The role of the ontology Ontology Developers Project manager End-users Editors Authors Data integration Presentation logic Editorial system

12. http://www.ontopia.net/© 2006 Ontopia AS12 Ontology considerations Requirements End-user needs Interface issues Ontology Existing data

13. http://www.ontopia.net/© 2006 Ontopia AS13 Startup Usually a workshop –project manager, editors, ontology modeller –presentation + Q&A Key goals –establish requirements –get overview of data sources Startup Analysis End-user Drafting Interaction design Verification

14. http://www.ontopia.net/© 2006 Ontopia AS14 Analysis Usually interviews with data source owners –extract documentation, schemas, exports,... –use torture if necessary Key goals –understanding of what really is in the data sources Startup Analysis End-user Drafting Interaction design Verification

15. http://www.ontopia.net/© 2006 Ontopia AS15 End-user Well-known IA/UX exercise –competency questions –personas –end-user interviews –card sorting –... Ontology modeller + IA/UX person + end-user examples Startup Analysis End-user Drafting Interaction design Verification

16. http://www.ontopia.net/© 2006 Ontopia AS16 Drafting The ontology modeller produces a draft –should use diagrams to communicate design –UML, ORM, boxes-and-arrows, or (later) GTM Draft must be reviewed with project team –editors, developers, project manager –nobody reads documentation –if they do, they don’t understand it, anyway Startup Analysis End-user Drafting Interaction design Verification

17. http://www.ontopia.net/© 2006 Ontopia AS17 Interaction design A well-known exercise –experienced interaction designers are out there Ensure that –ontology supports proposed design –ontology and proposed design use a consistent vocabulary Output –normal interaction design documentation –updated ontology Startup Analysis End-user Drafting Interaction design Verification

18. http://www.ontopia.net/© 2006 Ontopia AS18 Verification Final quality assurance on ontology –first conversion from data sources –review interaction design against ontology –verify ontology against output from end-user phase –verify ontology against requirements from startup phase –final team review of ontology Startup Analysis End-user Drafting Interaction design Verification

19. http://www.ontopia.net/© 2006 Ontopia AS19 Guidelines Some examples

20. http://www.ontopia.net/© 2006 Ontopia AS20 What is in the guidelines Heuristics for the correct use of Topic Maps constructs –topic types –type hierarchy –association types –occurrence types (internal and external) –name types The Ontopia ontology design course has the full set –taught in Kevin Trainor’s tutorial yesterday –only a small subset covered here for illustration purposes

21. http://www.ontopia.net/© 2006 Ontopia AS21 Criteria for a good topic type Instances should, by their intrinsic nature, be instances of the type –when shown an example instance and asked “what is this?” end-users should reply with the name of the topic type –instances should be instances of this topic type from the moment they come into being, until they cease existing Should not be context-dependent –not a role type (like “composer”, “employee”, or “subject”) The topic type should be a “natural kind”

22. http://www.ontopia.net/© 2006 Ontopia AS22 Heuristics for association types Keep number of roles as low as possible –decompose n-ary associations if possible Have a consistent set of role types –all instances should have the same set of role types omissible roles is acceptable –do not attach semantics to variation in role types Create a topic for an n-ary association if (and only if) –you want to say something more about the association

23. http://www.ontopia.net/© 2006 Ontopia AS23 Conclusion Further work

24. http://www.ontopia.net/© 2006 Ontopia AS24 Further work The methodology has moved on since the draft was written –need to flesh it out and bring it into line with this presentation Pattern library and base ontology need to be developed –this will follow in a separate phase after the paper is done Input from practitioners wanted! –