1. O N T O P E D I A The Identity of Everything www.ontopedia.net Topic Maps and the Semantic Web

2. O N T O P E D I A The Identity of Everything www.ontopedia.net Semantic Web – The “Layer Cake” Tim Berners-Lee Keynote Speech in 2005

3. XML How the two families stack up Topic Maps RDF TMCL RDF Schema OWL CTM RDF/XML N3 XTM RDF/A ISO Seamless Knowledge W3C Semantic Web LTM TMQL SPRQL ORGSYNTAXMODELCONSTRAINTS QUERY ORGSYNTAXMODELREASONING

4. O N T O P E D I A The Identity of Everything www.ontopedia.net Topic Maps and the Semantic Web Some people think RDF/OWL and Topic Maps are competitors – I do not think this is not true – I think they complement each other The Semantic Web gets much more publicity 1.W3C can bask in the glamour of the Web 2.RDF and OWL appealed immediately to academics But why do people think they compete? 1.RDF/OWL and Topic Maps have a number of similarities 2.They stem from rival organizations (W3C and ISO) 3.There are a few bigots 4.Most people do not understand the difference... RDF/OWL Topic Maps Romeo and Juliet

5. O N T O P E D I A The Identity of Everything www.ontopedia.net The are superficial similarities Both “extend” XML into the realm of semantics Both allow assertions to be made about things in the real world Both define abstract, associative (graph-based) models Both have URI-based models of identity Both allow forms of inferencing or reasoning Both have XML-based interchange syntaxes Both have constraint languages and query languages But they are also different in some crucial respects...

6. O N T O P E D I A The Identity of Everything www.ontopedia.net But the differences are significant Different roots – Topic Maps has its roots in traditional finding aids (indexes, thesauri, etc.) – RDF/OWL has its roots in document metadata and formal logic Different levels of semantics… – RDF is more low level – Topic Maps has more higher-level semantics Different models – Identity, scope, association roles, n-ary relationships, variant names, … Different goals – RDF: An artificially intelligent web for software agents – Topic Maps: Findability and knowledge integration for humans

7. O N T O P E D I A The Identity of Everything www.ontopedia.net The Most Crucial Differences  RDF/OWL is for machines;  Topic Maps is for humans.  RDF/OWL is optimized for inferencing;  Topic Maps is optimized for findability.  RDF/OWL is based on formal logic;  Topic Maps is not based on formal logic.  RDF/OWL is to mathematics as Topic Maps is to language.  RDF/OWL is to Aristotle as Topic Maps is to Wittgenstein.

8. O N T O P E D I A The Identity of Everything www.ontopedia.net What is this supposed to be? Is it an H or an A? T E C T H H A A The moral is: Fuzziness is a fact. Humans can handle it; machines can’t.

9. O N T O P E D I A The Identity of Everything www.ontopedia.net Different capabilities RDF/OWL, to support logic-based inferencing, cannot allow fuzziness – Topic Maps, because it is for humans, has to support fuzziness OWL ontologies tend to be very stringent and complex – Topic Maps ontologies tend to be simple and less formal OWL has properties for things that Topic Maps doesn’t need – Some Topic Maps features would be too complex for OWL In short, they are optimized for different purposes...

10. O N T O P E D I A The Identity of Everything www.ontopedia.net RDF or Topic Maps? Do you simply want to encode document metadata? – RDF is ideal and you won’t need OWL Do you want to achieve subject-based classification of content? – Topic Maps provides the best combination of flexibility and user-friendliness Do you want both metadata and subject-based classification? – Go straight for Topic Maps because it also supports metadata Do you want to develop agent-based applications? – Use RDF/OWL... but if you already have Topic Maps, you’re half way there Most importantly, whatever you choose, you can always move your data between RDF and Topic Maps, thanks to the RDFTM work…  RDF is more low-level; oriented towards machines  Topic Maps is more high-level; oriented towards humans  OWL is oriented towards artificial intelligence

11. O N T O P E D I A The Identity of Everything www.ontopedia.net RDFTM: Data interoperability RDF/Topic Maps Interoperability Task Force – A task force within the Semantic Web Best Practices and Deployment Working Group Chartered to deliver two documents: – Survey of Existing Interoperability Proposals – Guidlines for RDF/Topic Maps Interoperability Survey published in February 2006 – http://www.w3.org/TR/rdftm-survey/ Draft guidelines published in June 2006 – http://www.w3.org/2001/sw/BestPractices/RDFTM/guidelines-20060630.html – The task force is now disbanded and the work will be finalized by ISO

12. O N T O P E D I A The Identity of Everything www.ontopedia.net Topic Maps and Hypertext

13. O N T O P E D I A The Identity of Everything www.ontopedia.net Tim Berners-Lee 1989 Information Management: A Proposal World Wide Web Bill Atkinson 1987 HyperCard Vannevar Bush and Hypertext Vannevar Bush 1945 As We May Think Memex Doug Engelbart 1962 Augmenting Human Intellect NLS / AUGMENT Ted Nelson 1965 “Hypertext” Xanadu

14. O N T O P E D I A The Identity of Everything www.ontopedia.net “As We May Think” Concerned with the problem of finding information – Existing technology hopelessly out of date: – The amount of information is being “expanded at a prodigious rate”, but the means we use to find it is “the same as was used in the days of square-rigged ships” – The solution is to get away from hierarchical systems of organization and adopt new techniques that reflect how the brain works Vannevar Bush 1945 As We May Think MEMEX

15. O N T O P E D I A The Identity of Everything www.ontopedia.net Associative thinking “The human mind … operates by association. With one item in its grasp, it snaps instantly to the next that is suggested by the association of thoughts, in accordance with some intricate web of trails carried by the cells of the brain… The speed of action, the intricacy of trails, the detail of mental pictures, is awe-inspiring beyond all else in nature.” Vannevar Bush: As We May Think (1945)

16. O N T O P E D I A The Identity of Everything www.ontopedia.net Memex (memory extender) A “sort of mechanized private file and library”

17. O N T O P E D I A The Identity of Everything www.ontopedia.net Memex (memory extender) Consists of a desk containing – a very large set of documents stored on microfilm – screens on which those documents are projected – a device for photographing new documents – a mechanism for retrieving documents at the push of a button – the ability to create links between documents – the ability to build trails through documents, add comments to documents, insert new documents, etc. Note how everything revolves around documents Consists of a desk containing – a very large set of documents stored on microfilm – screens on which those documents are projected – a device for photographing new documents – a mechanism for retrieving documents at the push of a button – the ability to create links between documents – the ability to build trails through documents, add comments to documents, insert new documents, etc. Note how everything revolves around documents

18. O N T O P E D I A The Identity of Everything www.ontopedia.net Is this how you think? Is your head full of little documents all hyperlinked together? I doubt it ! Mine certainly isn’t ! We don’t think in terms of hyperlinked documents; we think in terms of concepts, and associations between concepts ?

19. O N T O P E D I A The Identity of Everything www.ontopedia.net Bush MEMEX As We May Think Engelbart Nelson Berners-Lee WWW Hypertext Xanadu AUGMENT NLS How we really think Documents are about subjects Those subjects exist as concepts in our brains They are connected by a network of associations This is how we store knowledge Documents are just a representation of some part of that knowledge

20. O N T O P E D I A The Identity of Everything www.ontopedia.net Bush – right and wrong Vannevar Bush was right that people think associatively He was right that organizing information in this way would make it easier to find But he was wrong in adopting a document-centric approach to the problem His basic idea – organize information “as we may way think” – was a great inspiration to Engelbart, Nelson, Atkinson, and Berners-Lee

21. O N T O P E D I A The Identity of Everything www.ontopedia.net Barking up the wrong tree But the Memex sent them all off in the wrong direction Hypertext has been barking up the wrong tree ever since And the Web, magnificent as it is, has made things “worse”

22. O N T O P E D I A The Identity of Everything www.ontopedia.net “As We May Think” Concerned with the problem of finding information – Existing technology hopelessly out of date: – The amount of information is being “expanded at a prodigious rate”, but the means we use to find it is “the same as was used in the days of square-rigged ships” – The solution is still to get away from hierarchical systems of organization and adopt new techniques that reflect how the brain works – That solution has to be subject-centric, not document-centric like the Web Vannevar Bush 1945 As We May Think MEMEX card catalogs (63 years on)

23. O N T O P E D I A The Identity of Everything www.ontopedia.net Which brings us to Topic Maps What’s special about it? – #1 The TAO* model corresponds to how people think Bush MEMEX As We May Think Engelbart Nelson Berners-Lee WWW Hypertext Xanadu AUGMENT NLS Puccini Tosca Lucca composed by born in composed by Madame Butterfly knowledge layer information layer * Topics + Associations + Occurrences

24. O N T O P E D I A The Identity of Everything www.ontopedia.net Subject-centric computing – a broader perspective

25. O N T O P E D I A The Identity of Everything www.ontopedia.net Topic Maps as a paradigm shift Topic Maps started out as a way to merge indexes It turned into a knowledge representation formalism But its significance is far greater Now the flag-bearer for subject-centric computing A paradigm shift in how we use computers Cf. object-oriented programming......and Copernicus

26. O N T O P E D I A The Identity of Everything www.ontopedia.net Object-oriented programming Response to 1960’s software crisis – Computer programs more and more complex – Difficult to maintain software quality Code simulates the world (as perceived by a human) – Objects represent real-world concepts (cf. topics) – They are grouped into classes (cf. topic types) – Data structures capture relationships between objects (cf. associations) Represented a paradigm shift in programming – OO languages now near universal (Java, C#, Ruby, Python,...)

27. O N T O P E D I A The Identity of Everything www.ontopedia.net (Actually some Greek, Indian and Muslim scholars knew better, but the view of Aristotle, Ptolemy and the Christian Church was dominant) The heliocentric revolution For 1,000s of years people thought that the sun revolved around the earth In 1543 Copernicus changed all that His heliocentric theory turned our understanding of the universe inside out. This was another paradigm shift Sun Earth Sun Earth

28. O N T O P E D I A The Identity of Everything www.ontopedia.net Subject-centric computing Today we face a similar situation in computing and information management Computers are at the centre of our information universe Applications and documents revolve around them The subjects we’re really interested in are nowhere to be seen Or at least, nowhere to be found

29. O N T O P E D I A The Identity of Everything www.ontopedia.net Computing “as we may think” This is wrong, because it does not reflect how humans think Humans think in terms of subjects, concepts, ideas We must put subjects at the centre, because that’s what we’re really interested in This is the essence of subject-centric computing It really is a paradigm shift – Topic Maps is showing the way

30. O N T O P E D I A The Identity of Everything www.ontopedia.net

31. O N T O P E D I A The Identity of Everything www.ontopedia.net topic maps tm2008 bantu semantics LING 2110 INF 2820 rana keynote OOXML K185 gambia opera janacek bayreuth håkon TM2008 Topic page Emails Documents Web pages Copy PSI Ψ

32. O N T O P E D I A The Identity of Everything www.ontopedia.net Subject-centric file system The file system is a hierarchy and that’s a pain – Trees aren’t expressive enough WinFS looked like it might change all that – New data storage and management system announced in 2003 – Didn’t make it into Vista. Seems to have disappeared Let the new file system be a topic map! – “Folders” are topics with global identifiers – User-defined metadata on “folders” (internal occurrences) – External occurrences – Related through navigable, typed associations

33. O N T O P E D I A The Identity of Everything www.ontopedia.net Subject-centric operating system Now that the file system is a topic map, why not go the whole hog? – Services to applications for assigning PSIs – NLP based help for (semi-automatically) categorizing documents – Ability to extract fragments from the system topic map – Peer-to-peer features for exchanging fragments with others – Facilities for context-based virtual merges under user control –...