Incorporating ARGOVOC in DSpace-based Agricultural Repositories

Dr. Devika P. Madalli&

Nabonita Guha

Documentation Research & Training CentreIndian Statistical Institute, Bangalore

Nov. 10, 2006 Seventh Agricultural Ontology Service (AOS) Workshop 2

Overview

� Some Observation on present ontology plugin� AGROVOC Thesaurus Plugin for DSpace� AGROVOC in SKOS� Difference between Thesaurus and Ontology� Moving towards Ontology

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Some Observations

� Present ontology plugin integrated with DSpace 1.4 doesn’t support synonyms and related terms

� It shows only broader and narrower relationship� It requires the conversion of OWL or SKOS representation of

AGROVOC into the native plugin format every time AGROVOC is updated

� Ideally, thesaurus input can be either in SKOS or OWL format (can be achieved by XLST)

� Cron job checks updates on AGROVOC site and downloads either SKOS or OWL file

� Alternatively, ontology should be displayed on the fly from the AGROVOC site (idea from Dr. Johannes Keizer)

Nov. 10, 2006 Seventh Agricultural Ontology Service (AOS) Workshop 4

AGROVOC Thesaurus Plug-in

� To provide controlled vocabulary support in subject description in DSpace and depict:� Equivalence� Homographs� Broader/narrower/associated relationship

� To …� Provide standard access points to document; &� Thesaurus based Indexing & Searching

Nov. 10, 2006 Seventh Agricultural Ontology Service (AOS) Workshop 5

Handling Synonyms

� At the time of creating the metadata� The synonymous terms are added along with the standard

term

� At the time of search� If the user enters a non-standard term, it will be replaced

by standard term, and search is performed using the standard term

Nov. 10, 2006 Seventh Agricultural Ontology Service (AOS) Workshop 6

� Homograph resolution (spelling same but different meaning)� Can be resolved using context of the given term

� At the search stage, the system will retrieve the subject string attached to the document along with the associated documents� Fish – agriculture� Fish – cooking� Fish – decoration

Handling Homographs

AGROVOC in SKOS

Nov. 10, 2006 Seventh Agricultural Ontology Service (AOS) Workshop 8

SKOS

� SKOS = Simple Knowledge Organization System

� Provides a model for expressing the basic structure and content of concept schemes [1] in RDF syntax

� Concept Scheme = thesaurus, classification scheme, taxonomy, subject heading list, terminologies, etc

Nov. 10, 2006 Seventh Agricultural Ontology Service (AOS) Workshop 9

SKOS: Classes

� Classes [2]� ConceptScheme (AGROVOC, MeSH, AAT, etc)

� Concept (actual terms, e.g. animals, crops, etc)

� Collection (group of concepts e.g. meat cattle)

Nov. 10, 2006 Seventh Agricultural Ontology Service (AOS) Workshop 10

SKOS: Properties

� Properties [2]� altLabel� broader� changeNote� narrower� prefLabel� scopeNote� hasTopConcept� historyNote� isPrimarySubjectOf

� isSubjectOf� member� definition� note� primarySubject� related� subject� example� subjectIndicator

Thesaurus Vs Ontology

Nov. 10, 2006 Seventh Agricultural Ontology Service (AOS) Workshop 12

Thesaurus is …

� Controlled vocabulary tools in which relationship between concept terms are shown as:� Equivalence = synonyms� Homographic = same spelling� Hierarchical = broader -> narrower� Associative relationships = related terms

� Represents the terms denoting certain concepts

Nov. 10, 2006 Seventh Agricultural Ontology Service (AOS) Workshop 13

Ontology is …

� An ontology defines the terms used to describe and represent an area of knowledge (subject matter) [3]

� Model for the meaning of those terms

� Definition of the vocabulary used

(Real world entity)

CattleCattle

Suckler CowSuckler Cow

Dairy CowDairy Cow

HeifersHeifers

Cow MilkCow Milk

Milk yielding cowsMilk yielding cows

COW BT

NT

NT

RT

RT

RT

Related Terms in AGROVOC for Cow

SKOS representation of AGROVOC Terms

19391939

CowsCowsskos:prefLabel

Domestic AnimalDomestic Animal

Milk yielding cowsMilk yielding cows

skos:Related

HeifersHeifers

skos:Related

Cow milkCow milk

skos:Related

CattleCattle

skos:Broader

Suckler CowSuckler Cow

skos:Narrower

Dairy CowDairy Cow

skos:Narrower

http://www.fao.org/aos/agrovoc#c_1939

COWCOW

AnimalsAnimals

subClassOfsubClassOf

WildWildDomestic AnimalDomestic Animal

subClassOf

CattleCattle

subClassOf

Cow milkCow milk

hasByproductDomainRange

HeifersHeifers

subClassOf

Milk yielding cowsMilk yielding cows

subClassOf

RDF Representation of AGROVOC Terms

Nov. 10, 2006 Seventh Agricultural Ontology Service (AOS) Workshop 17

Current Approach

� To develop a plugin which can provide thesaural support in DSpace

� Not only specific to AGROVOC, but can support any thesaurus in DSpace represented in SKOS

Nov. 10, 2006 Seventh Agricultural Ontology Service (AOS) Workshop 18

Moving Towards Ontology

� Decision regarding the nature of Information Retrieval� Document retrieval ; or� Retrieval of exact information extracted from the document

� To develop a generic framework for Agriculture domain knowledge with scopes for further extension for narrower domains

� To incorporate the inferencing mechanism defining certain rules (SWRL)

Uncontrolled VocabularyUns

tructu

red

Controlled Vocabulary in formal syntax (RDF)

Structu

red

Ontology-based information search & retrieval

Semantic

Nov. 10, 2006 Seventh Agricultural Ontology Service (AOS) Workshop 20

References

1. Alistair Miles & Dan Brickley. SKOS Core Guide. W3C Working draft 10 May 2005. http://www.w3.org/TR/swbp-skos-core-guide

2. Alistair Miles & Dan Brickley. SKOS Core Vocabulary Specification. W3C Working Draft 2 November 2005. http://www.w3.org/TR/swbp-skos-core-spec/

3. Dr. Leo Obrst. Presentation on the ontology spectrum & semantic models. MITRE, Information Semantics Group, January 12 & 19, 2006. http://ontolog.cim3.net/file/resource/presentation/LeoObrst_20060112/OntologySpectrumSemanticModels--LeoObrst_20060112.ppt

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Thank You

Devika P. Madallidevika@drtc.isibang.ac.in

Nabonita Guhaguha@drtc.isibang.ac.in