Cross-Language IR: An OverviewWhat is CLIR?CLIR vs. MLIRWhy do we need CLIR systems?General Issues With CLIRBasic Approaches to CLIRBasic Approaches Cont’d…ConclusionsCross-Language IR: An OverviewBernardine ReitmeyerWIRED12/2/04What is CLIR?IR on a monolingual document collection that can be queried in multiple languagesIR on a multilingual document collection, where queries can retrieve documents in multiple languagesIR on multilingual documents(Hull & Grefenstette, 1996)CLIR vs. MLIRCross-language information retrieval refers to the 3 definitions we’ve discussed.Multilingual information retrieval (MLIR) includes CLIR and IR in systems that use a language other than that of the searcher (query must also be in the other language)Most people still use MLIR to describe any work in this areaEmphasis here is cross-languageWhy do we need CLIR systems?To search collections containing documents in many languagesTo search documents containing text in more than one languageFor those who aren’t fluent in a foreign language but can make use of some contents of documents retrieved (images, names, etc.)(Oard & Dorr, 1996)General Issues With CLIRMultilingual text access (character sets, etc.)Differences between languages-stemming, compound words, breaks between words, etc.Term ambiguity between languagesWhen to translate (query vs. document)Basic Approaches to CLIRMachine Translation/Machine Learning(automatic translation of documents or queries)Controlled Vocabulary(use of multilingual thesaurus)Dictionary-Based Approaches(combination of monolingual or bilingual dictionaries – similar to a thesaurus)Basic Approaches Cont’d…Latent Semantic Indexing(makes comparisons between semantically related words)Corpora-Based Approaches(uses existing texts to automatically build information about relationships between terms)ConclusionsAlthough CLIR faces many tough issues, it is an important and growing facet of IR. Starting in 2000, it even got its own conference (because it was getting lots of attention at the TREC conferences) called CLEF (Cross-Language Evaluation Forum).For more information:
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