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O N T O P E D I AThe Identity of Everything

Identity

Steve Pepperpepper.steve@gmail.com

Oslo University College, 2008-10-27

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O N T O P E D I AThe Identity of Everything

Course agenda

Week 37 – 09-08 Introduction to Topic Maps – Part 1 Week 38 – 09-15 Creating a topic map Week 39 – 09-22 Introduction to Topic Maps – Part 2 Week 42 – 10-13 Modelling issues (LTM) Week 43 – 10-20 Ontology-driven editing Week 44 – 10-27 Identity 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

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O N T O P E D I AThe Identity of Everything

Today’s agenda

Identity– Subject identifiers and subject descriptors

– (subject locators)

– (item identifiers)

Discussion of group projects

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O N T O P E D I AThe Identity of Everything

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

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O N T O P E D I AThe Identity of Everything

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

TA topic in the computer domain

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O N T O P E D I AThe Identity of Everything

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

MadameButterfly

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O N T O P E D I AThe Identity of Everything

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 indicatesdoes not

– Computers can use the address of thesubject descriptor to establish identity

– Such addresses are calledsubject identifiers

Subject descriptors and subject identifiers are the two sides ofthe 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.o

ntoped

ia.n

et/P

uccin

i

subject identifier

topic

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O N T O P E D I AThe Identity of Everything

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)

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O N T O P E D I AThe Identity of Everything

PSIs for machines and humans

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O N T O P E D I AThe Identity of Everything

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"]

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O N T O P E D I AThe Identity of Everything

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

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O N T O P E D I AThe Identity of Everything

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?

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O N T O P E D I AThe Identity of Everything

Role types

select $AT, $RT1, $RT2 fromassociation-role( $A, $R1 ),association-role( $A, $R2 ),type($A, $AT),type($R1, $RT1),type($R2, $RT2),$R1 /= $R2order by $AT?

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O N T O P E D I AThe Identity of Everything

Project Groups

African Nations Cup 2008African WritersDILL ProgramHIO DatabasesNorwegian Feature FilmsThe Nobel Prize

Topic Maps BibliographyTopic Maps ToolsWhisky

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O N T O P E D I AThe Identity of Everything

Groups

A. Phuong, Nga, Szu-PingHIO Databases

B. Andrea, Juan-Daniel, Mehrnoosh, SaraDILL Program

C. Pussadee, Roriana, WachirapornNobel Prizes

D. Nickson, Florence, MonicaTopic Maps Bibliography

E. Alice, Barulaganye, EstherAfrican Writers

F. Muluken, YibeltalTopic Maps Tools

G. Anja, Clara, Kanita, TrudeNorwegian Feature Films

H. Isaac, WilfredAfrican Nations Cup

J. ChristianWhisky

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O N T O P E D I AThe Identity of Everything

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: 250–1,000 TTs: 10–35

– Associations:500–2,500 ATs: 10–45

– Occurrences:500–2,500 OTs: 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

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O N T O P E D I AThe Identity of Everything

Statistics from 2007

Including system types

Excludingsystem types Total TAOs

Topic Map TT AT OT TT AT OT Topics Assocs Occs

Beethoven’s Concerti 34 20 17 19 12 12 297 513 571

Dante's Inferno 30 23 19 15 15 14 701 1334 950

Digital Libraries 30 33 31 15 25 26 289 803 929

Dog Breeds 25 17 17 10 9 12 325 1756 1681

Donald Duck 25 37 17 10 29 12 281 955 678

Historical Monument 31 17 15 16 9 10 284 450 470

JLI Faculty 33 25 20 18 17 15 234 517 381

Christiania Bohemians 28 25 18 13 17 13 597 1147 1561

Norwegian Christmas 50 51 21 35 43 16 987 2312 2239

StreetStyle 33 24 19 18 16 14 480 987 562

Wine 33 25 16 18 17 11 413 1024 1120

Averages 32 27 19 17 19 14 444 1073 1013

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O N T O P E D I AThe Identity of Everything

African Nations Cup 2008

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O N T O P E D I AThe Identity of Everything

African Writers

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O N T O P E D I AThe Identity of Everything

DILL Program

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O N T O P E D I AThe Identity of Everything

HIO Databases

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O N T O P E D I AThe Identity of Everything

Norwegian Feature Films

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O N T O P E D I AThe Identity of Everything

The Nobel Prize

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O N T O P E D I AThe Identity of Everything

Topic Maps Bibliography

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O N T O P E D I AThe Identity of Everything

Topic Maps Tools

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O N T O P E D I AThe Identity of Everything

Whisky

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O N T O P E D I AThe Identity of Everything

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

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O N T O P E D I AThe Identity of Everything

Next Topic Maps lecture

Thursday November 20 (09.30)– Same place

Agenda

– Topic Maps and the Semantic Web

– Project Review