Retrieval effectiveness for OCR text using thesauri

This thesis reports on the effects of an automatic query expansion with a subject specific thesaurus on retrieval effectiveness for document collection consisting of OCR text; The investigation encompasses several experiments with a modern retrieval engine based on the probabilistic model. Each experiment is performed on two document collections. The first version of the collection consists of raw OCR output. The second collection consists of the ground truth (retyped from hard copy) version of the same collection; It is shown that the usage of the thesaurus as a source for query expansion can significantly improve recall for Boolean queries, for both OCR and manually corrected document collections. In the case of weighted queries, the expansion has no effect on the average precision and recall. Nevertheless, some individual queries benefit from query expansion.

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Computer Science

Grantor dc:publisher

University of Nevada, Las Vegas

Year

1999

Author dc:creator

• Dimitrova, Elena

Contributors dc:contributor

• Kazem Taghva

Statement dc:rights

• IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

Language dc:language

English

Identifier

https://oasis.library.unlv.edu/rtds/1097

OAI identifier oai:identifier

oai:oasis.library.unlv.edu:rtds-2096