simple knowledge organisation system-ecoterm-2006

7/29/2019 Simple Knowledge Organisation System-Ecoterm-2006

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Rutherford Appleton Laboratory

SKOSEcoterm 2006

Alistair MilesCCLRC Rutherford Appleton Laboratory

Semantic Web Best Practices and Deployment


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http://www.w3.org/2004/02/skosAlistair Miles, Ecoterm 2006, slide 2

Reminder: what is it?

Simple Knowledge Organisation System Formal language for representing

controlled structured vocabularies(thesauri, classification schemes, ?)

Subject metadata &informationretrieval this document is about romantic love.

this document is about the cure of tuberculosis by x-

ray in India in the 1950s.

Application ofRDF


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Since Ecoterm 2005

SKOS Core Guide &SKOS CoreVocabulary Specification First Working Draft May 2005

Second Working Draft October 2005

Minor changes

Quick Guide to Publishing aThesaurus on the Semantic Web First Working Draft May 2005


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What comes next ?

Life after SWBPD-WG ? Plans for next phase of W3C

Semantic Web Activity

New WG? SKOS W3C Recommendation by end

2007?

N.B. Not yet approved!


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If Rec then

What is the scope? What is thefundamental design goal?

First part of SKOS Rec would be

requirements specification. Between now and Sept/Oct 2006

define scope and requirements.


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What Id like to do here

Talk about some of the assumptionsbehind SKOS.

Sketch some ideas on how to define

scope and requirements for SKOS. Get your feedback.

[email protected]

SKOS: Requirements for Standardization

isegserv.itd.rl.ac.uk/public/skos/press/dc2006/paper.pdf


7/27http://www.w3.org/2004/02/skosAlistair Miles, Ecoterm 2006, slide 7

Brief history of scope

2003-04: SWAD-Europe ISO 2788 thesauri Non-standard thesauri via extensibility e.g.

GeMET

Classification scheme (PACS)

Multilingual thesauri

Semantic mapping

2004: W3C Glossaries

2005: Discussion re terminologies Subject headings? Gazeteers?

Folksonomies? Taxonomies?



Assumptions: purpose

Formal representation of controlledstructured vocabularies intended foruse in information retrievalapplications.



Assumptions: workflow

a) Build a vocabularyb) Build an index

c) Retrieve



Assumptions: components

Vocabulary Development Application Something to help build a vocabulary

Indexing Application Something to help build an index

Retrieval Application Something to help retrieve things

SKOS ultimately designed to supportinteroperation of these three keycomponents.



Proposed scope

SKOS is a formal language forrepresenting controlled structuredvocabularies intended for use withininformation retrieval applications.

SKOS is required to support theinteroperation of these three keycomponents.

I.e. define the requirements for SKOS bydescribing a set offunctionalities thatmust be enabled.



Other components

Vocabulary mapping ? Metadata registries ?

?



Component specs

first discuss social andtechnological context, then return tocomponent specs



Context

What is the social and technologicalcontext in which controlledstructured vocabs are used?

Assume two basic needs Locate something I already know about. Discover something new.

N.B. a good location service is not

necessarily a good discoveryservice.

Cf. Google and del.icio.us



Strategies

Basic strategies for implementingretrieval services

1. Statistical text analysis

2. Analysis of user behaviour3. Index with controlled vocab

Other strategies 1. kos-assisted text analysis?



Cost problem

Given that applying controlled structuredvocab for retrieval involves significantinitial and ongoing investment

Given that other strategies are cheaper

Huge pressure to drive down cost andincrease utility.

Requirement for seamless integration. I.e. controlled vocab is seldom used in isolation, most

applications will combine strategies.



Use case

Search portal Use combined strategies.



Component specs

Important factors

Minimise cost. Decentralisation. Assistance.

Maximise utility. Query expansion. Smart ranking. Maximize lifetime.

Use the Semantic Web! Situation A. search across many collections, where

indexers use same controlled vocab. Situation B. search across many collections, where

indexes use different controlled vocabs.



Focus areas

Decentralisation requires differentmodels of collaboration and change.

Representing change a key factor tokeeping a vocab applicable.

Ranking and scoring well understoodfor text, less so for controlled index.

Theory of query expansion? Fieldtrials of query expansion?

Strategies for providing assistance?



Change and collaboration

Continuum of collaboration models:centralized decentralised

Continuum of change managementmodels: continuous discrete

Decentralization can reduce cost ofdevelopment and maintenance

Change management can ensure

continued utility maximize ROI Support for declarative representation of

change a requirement for SKOS.



Semantic Web architecture

Exploit Semantic Web facility todistribute and merge data.

However, publication of data in theSemantic Web, best practices needwork.

See Best Practice Recipes forPublishing RDF Vocabularies W3CWorking Draft (Google publishingRDF).


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Semantic Web architecture


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Direct interaction


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Information retrieval

Indexing and query evaluation wellunderstood for text content.

Less well understood for controlledmetadata.

Query types?

Query evaluation strategies, e.g.

query expansion? Ranking?


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Assistance for indexers

Provide suggestions Comparison of labels and annotations Machine learning

Exploit lexical resources

?


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Assistance for mappers

Provide suggestions Analysis of labels and annotations Exploit lexical resources

?


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htt // 3 /2004/02/ kAli t i Mil E t 2006 lid 27

Summary

SKOS: fundamental requirement to

support information retrieval usingcontrolled structured vocabularies.

Define requirements by describinginformation retrieval functionalities.

Divide functionalities into: Presentation styles Query types e.g. compound queries, coordination Query evaluation strategies

Assumptions: Key components Semantic Web interaction Context pressure to make vocabularies profitable Issues: change, assistance, theory

simple knowledge organisation system-ecoterm-2006

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