1. O N T O P E D I A The Identity of Everything www.ontopedia.net Identity Steve Pepper pepper.steve@gmail.com Oslo University College, 2008-10-27

2. O N T O P E D I A The Identity of Everything www.ontopedia.net Course agenda Week 37 – 09-08Introduction to Topic Maps – Part 1 Week 38 – 09-15Creating a topic map Week 39 – 09-22Introduction to Topic Maps – Part 2 Week 42 – 10-13Modelling issues (LTM) Week 43 – 10-20Ontology-driven editing Week 44 – 10-27Identity Week 48 – 11-24(Semantic Web) – Move to end of Week 47??? Terminology: – Topic Maps: The technology and the standard – topic maps: The artefacts (documents) we create

3. O N T O P E D I A The Identity of Everything www.ontopedia.net Today’s agenda Identity – Subject identifiers and subject descriptors – (subject locators) – (item identifiers) Discussion of group projects

4. O N T O P E D I A The Identity of Everything www.ontopedia.net Identity: The all-important issue What makes merging possible? – NOT the use of names, which are notoriously unreliable – Names are not unambiguous (the homonym problem) – Many topics have multiple names (the synonym problem) Achievement of the collocation objective – Only possible through the use of unique global identifiers The issue of identification of subjects is therefore crucial – If subjects have unique identifiers, people can be free to use whatever names they like – and machines can still aggregate information

5. O N T O P E D I A The Identity of Everything www.ontopedia.net Subjects and Topics Topics are surrogates, or “proxies” (inside the computer) for the ineffable subjects that you want to talk about, such as Puccini, love, these slides, or the second law of thermodynamics A subject in the real world T A topic in the computer domain

6. O N T O P E D I A The Identity of Everything www.ontopedia.net The identity of subjects Topics exist in order to allow us to talk about subjects – The relationship between the two is sometimes called intentionality We need to know exactly which subject a topic represents – That is, we need to establish its subject identity – The collocation objective depends on knowing when applications are talking about the same thing Lucca Tosca Puccini Madame Butterfly

7. O N T O P E D I A The Identity of Everything www.ontopedia.net Life, the Universe and Everything The Computer Domain The Topic Map Domain Subject identifiers The identity of most subjects can only be established indirectly – An information resource can provide an indication of the subject’s identity to a human – Such a resource is called a subject descriptor A subject descriptor has an address, even though the subject it indicates does not – Computers can use the address of the subject descriptor to establish identity – Such addresses are called subject identifiers Subject descriptors and subject identifiers are the two sides of the human-computer dichotomy subject Giacomo Puccini, Italian composer, b. Lucca 22nd Dec 1858, d. Brussels, 29th Nov 1924. Best known for his operas, of which Tosca is the most... subject descriptor Puccini http://psi.ontopedia.net/Puccini subject identifier topic

8. O N T O P E D I A The Identity of Everything www.ontopedia.net Published Subjects In order for identifiers to be reused, they must made publicly available – A subject identifier that has been made available for use outside one particular application is called a published subject identifier (PSI) – Its descriptor is called a published subject descriptor (PSD) Anyone can publish PSI sets – Adoption of PSI sets will be an evolutionary process based on trust – It will lead to greater and greater interoperability – between topic map applications, between Topic Maps and RDF, and across information and knowledge management in general – Check out http://psi.ontopedia.net (under development)

9. O N T O P E D I A The Identity of Everything www.ontopedia.net PSIs for machines and humans

10. O N T O P E D I A The Identity of Everything www.ontopedia.net Advice on subject identifiers Always use them for your typing topics – Makes your ontology more portable The more serious your application, the more extensively you should use them for instances – Merging with other topic maps will not be successful without identifiers LTM code for subject identifiers – See previous lecture and opera.ltm – Example: – [composer = "Composer" @"http://psi.ontopedia.net/Composer"]

11. O N T O P E D I A The Identity of Everything www.ontopedia.net Identifiers Use an identifier for every typing topic – Use the prefix http://psi.ontopedia.net/ – Reuse existing identifiers wherever possible Choice of suffix for topic types and role types: – A short name, preferably the same as Wikipedia uses – Start with a capital letter; accented letters are OK – Replace spaces by underscores – Examples: Composer, Fairy_tale, Work_of_art, Place For association types, occurrence types and name types: – Use a verb (association types) or a noun (occurrence and name types) – Start with a lower-case letter (to indicate a property) – Examples: composed_by, date_of_birth, given_name Check Norwegian Opera for examples – Do not use the Italian Opera Topic Map – its conventions are outdated

12. O N T O P E D I A The Identity of Everything www.ontopedia.net More tips for your ontology Provide a description for every topic type: – Give a short definition – Comments (if necessary) on the way in which the type is (intended to be) used in the topic map – http://www.ontopedia.net/omnigator For examples of recommended best practice – Refer to the Norwegian Opera Topic Map See http://www.ontopedia.net/NorwegianOpera/ontology.jsp – Use the Omnigator version listed under Topic Maps at www.ontopedia.net Download it to your machine using the Export plug-in – This query lists all subject identifiers for typing topics: select $TYPE, $SID from { instance-of($T, $TYPE) | type($T, $TYPE) }, subject-identifier($TYPE, $SID) order by $TYPE?

13. O N T O P E D I A The Identity of Everything www.ontopedia.net Role types select $AT, $RT1, $RT2 from association-role( $A, $R1 ), association-role( $A, $R2 ), type($A, $AT), type($R1, $RT1), type($R2, $RT2), $R1 /= $R2 order by $AT?

14. O N T O P E D I A The Identity of Everything www.ontopedia.net Project Groups African Nations Cup 2008 African Writers DILL Program HIO Databases Norwegian Feature Films The Nobel Prize Topic Maps Bibliography Topic Maps Tools Whisky

15. O N T O P E D I A The Identity of Everything www.ontopedia.net Groups A.Phuong, Nga, Szu-Ping HIO Databases B.Andrea, Juan-Daniel, Mehrnoosh, Sara DILL Program C.Pussadee, Roriana, Wachiraporn Nobel Prizes D.Nickson, Florence, Monica Topic Maps Bibliography E.Alice, Barulaganye, Esther African Writers F.Muluken, Yibeltal Topic Maps Tools G.Anja, Clara, Kanita, Trude Norwegian Feature Films H.Isaac, Wilfred African Nations Cup J.Christian Whisky

16. O N T O P E D I A The Identity of Everything www.ontopedia.net Semester Assignment The assignment is to create a topic map using Ontopoly. It will be judged on the following criteria: – Accuracy of modelling type hierarchy other hierarchies appropriate role types appropriate naming – Consistency of names assertions Appropriate size: – Topics:250–1,000TTs:10–35 – Associations:500–2,500ATs:10–45 – Occurrences:500–2,500OTs:10–25 – Degree of interest sufficient number of topics rich set of interconnections large number of interesting occurrences of different types – Documentation every typing topic should have a PSI and a description

17. O N T O P E D I A The Identity of Everything www.ontopedia.net Statistics from 2007 Including system types Excluding system typesTotal TAOs Topic MapTTATOTTTATOTTopicsAssocsOccs Beethoven’s Concerti3420171912 297513571 Dante's Inferno30231915 147011334950 Digital Libraries303331152526289803929 Dog Breeds2517 1091232517561681 Donald Duck253717102912281955678 Historical Monument31171516910284450470 JLI Faculty332520181715234517381 Christiania Bohemians28251813171359711471561 Norwegian Christmas50512135431698723122239 StreetStyle332419181614480987562 Wine33251618171141310241120 Averages32271917191444410731013

18. O N T O P E D I A The Identity of Everything www.ontopedia.net African Nations Cup 2008

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

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

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

22. O N T O P E D I A The Identity of Everything www.ontopedia.net Norwegian Feature Films

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

24. O N T O P E D I A The Identity of Everything www.ontopedia.net Topic Maps Bibliography

25. O N T O P E D I A The Identity of Everything www.ontopedia.net Topic Maps Tools

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

27. O N T O P E D I A The Identity of Everything www.ontopedia.net Home assignment Finalize the ontology – Document it by providing a short description of each typing topic – Send me the XTM file by email before November 3 Populate the topic map – Make a note of any issues that arise for discussion in class on November 10 Prepare a presentation – Thesis seminar: November 28

28. O N T O P E D I A The Identity of Everything www.ontopedia.net Next Topic Maps lecture Thursday November 20 (09.30) – Same place Agenda – Topic Maps and the Semantic Web – Project Review