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The general problem
• Searching for multilingual resources is not easy: – on the web– on metadata catalogues / bibliographical databases– on full text documents
• Results are generally in the language used in the search query
=> We need a multilingual approach and multilingual tools (Thesauri / Ontologies, etc.)
What we can achieve (1): Multilingual concept resolution
• With a multilingual thesaurus or ontology we can find resources on any language
Because we can realize ......
Multilingual concept resolution!
What we can achieve (2): BrokeringWith a multilingual thesaurus or ontology we can find resources from several sources also if we do not know the terminology and the language used in these sources
vesselscraftsfishing vessels
shipsnavionavire船舶
bateau de pêchefishing boat
fishing vessel
Results in multiple languages from multiple databases
How to build a multilingual Thesaurus / Ontology
• Lexicalizations of concepts in multiple languages: – {… fishing boat; bateau de pêche; 捕捞渔船 … }
• For every language we can have synonyms: – { … fishing vessel, fishing boat, fishing craft … }
– { … bateau de pêche, navire de pêche, … }
– { … 捕捞渔船, … }
FAO activities (ongoing)
• Food safety ontology (English, Spanish, French)• Fishery ontology (English, Chinese)• Food and Nutrition ontology-based portal (English,
Spanish, French)• Extensive work with AGROVOC
– RDFS / OWL version– Semantic refinements– Expand multilingual coverage– Expand subject coverage
The multilingual vocabulary...
• Must cover all concepts of interest to the users in the various languages,
• ... at a minimum all domain concepts lexicalized in any of the participating languages
• Must accommodate hierarchical structures suggested by different languages
(Dr. Soergel)
Problems (1)• Translation of an English thesaurus into
German does not make a German thesaurus=> whenever possible we need to consider the
concept in his globality (many languages, definitions, “surrounding context” etc.)
• Equivalence of terms holds only in some contexts
• More difficult to translate non-specialized terms
(Dr. Soergel)
Problems (2)• Two terms mean almost the same thing but differ slightly
in meaning or connotation:– English: alcoholism – French: alcoholisme
– English: vegetable (includes potatoes)– German: Gemüse (does not include potatoes)
• If the difference is big enough, one needs to introduce two separate concepts under a broader term; otherwise a scope note needs to clearly instruct indexers in all languages how the term is to be used so that the indexing stays, as far as possible, free from cultural bias or reflects multiple biases by assigning several descriptors. (Dr. Soergel)
Available resources: example
• SuperThes, ...
• SWAD-Europe initiative: thesaurus activities– RDF encoding of multilingual thesaurus
• Multilingual labelling approach (mirroring relations for every language)
• Interlingual mapping approach (different structures to be mapped)
SWAD-Europe: Inter-Thesaurus Mapping• SKOS mapping:
– Exact – Inexact – Major – Minor – Partial – Broad – Narrow – AND – OR – NOT
Inter-Thesaurus Mapping: example
<ag:Concept><descriptor xml:lang="fr">Academie</descriptor><map:exactMatch>
<map:AND><map:memberList rdf:parseType="Collection"> <aat:Concept>
<descriptor xml:lang="en">Academy</descriptor> </aat:Concept> <aat:Concept>
<descriptor xml:lang="en">Buildings</descriptor> </aat:Concept></map:memberList>
</map:AND></map:exactMatch></ag:Concept>
Available resources: another possibility
• Use OWL– Define concepts– Define terms– Define string– Define relationships between these 3 elements:
• <similatTo>, <equivalentTo>, (+ skos suggestions)• <hasSynonym>, <hasAntonym>, <hasCognate> • <hasSpellingVariant>, <hasTranslation>
Available resources: other techniques NLP
• Knowledge discovery: helps on the creation of ontologies in a specific language
• Used to create good IS– Concept extraction– Multilingual search engine
• …
Conclusion
• We need multilingual tools– Ontologies better than traditional thesauri
• The task is not easy– Subject experts are essential– NLP could help
• We need tools– To help experts to realize the mapping– To do annotations– …
Thank you.
