Bilingual Search Engine Augmented with Query Expansion

Abstract

Nowadays, distributed information in the form of linguistic resources is accessible throughout the internet. Search engines have become crucial for information retrieval since users need to find and retrieve relevant information in various languages and forms. The objective of this paper is to investigate the application of query expansion technique to improve cross-language information retrieval in English and Thai. As the method of evaluation of query expansion, we investigate whether the expanded terms are useful for the search. Search CapabilitiesOperator Specification: Operator specification allows a user to logically relate multiple concepts together to define what information is needed. Our system supports queries with various combinations of Boolean operators AND, OR and NOT. Operators are processed from left to right.Query Expansion: The query expansion component employs the dictionary-based technique using part-of-speech information and semantic relations. We use LEXiTRON for this expansion process. When a user submits a query to the system, the query is expanded by adding the terms which are synonyms and related words. However, since a word can have many senses, the appropriate level of expansion must be determined. At the first level expanding, we retain every possible sense, i.e. every possible part-of-speech. In the second level, we perform a part-of-speech disambiguation. If the 1 stlevel expanded words include more than one part-ofspeech, only words that have the same part-of-speech will be selected to the 2 nd -level expanded word. Proper weight calculation is then performed on the resulting words from the 2 nd level. Query Translation:The queries are translated using the same dictionary as in the previous step.Similarity Measurement:The similarity measurement tells how alike two documents are, or how alike a document and a query are. To measure the