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In query expansion (QE) terms are added to an initial query in order to improve retrieval effectiveness. In this thesis we use QE in the sense that a reformulation of the query is done by deleting the terms in the initial query and instead replacing them with terms from the …
En jämförelse av återvinningseffektiviteten för fyra olika sökfrågetyper
This Masters thesis deals with query expansion in an online library catalogue. The aim of the study was to compare the retrieval effectiveness of four different query types when applied to the online library catalogue of the University College of Borås. The query types were: an …
… WordNet. Four different types of queries were constructed: a baseline query S1, the baseline query expanded with synonyms S2, the baseline query expanded with hyponyms S3 and finally the baseline query expanded with the synonyms and hyponyms used in S2 and S3. The terms for …
The aim of this masters thesis is to examine query expansion. Query expansion is the process of adding new terms to a query to improve the retrieval effectiveness. In this study the baseline query was expanded in five different modes. The first expansion strategy was formulated …
This thesis deals with query formulation in full text retrieval. The variables studied were query expansion and query structur[INS: e :INS , and the aim of the thesis is to study their co-effects on retrieval performance in a probabilistic system. The expansion was made with …
This thesis examines the effects of proximity operators and query expansion with synonyms on retrieval performance. The queries were expanded with synonyms and structured with proximity operators where the permitted distance between terms varied from 1 to 3. The expansion terms …
en komparativ studie av olika strategier för termklustring baserade på lokal analys
Automatic query expansion has long been studied in information retrieval research as a technique that deals with the fundamental issue of word mismatch between query and document. The purpose of this thesis is to compare the retrieval effectiveness of different strategies for …
… results between three distinct search strategies in simulated automatic query expansion in a bibliographic database. Our purpose is to investigate which of the search strategies score the most effective precision and to what extent the same relevant documents are retrieved …
… study of ten laboratory experiments with different kind of sources for query expansion terms. The experiments are grouped according to categories of term sources, which are: search results, collection dependent knowledge structures, collection independent knowledge structures …
… purpose was to examine Swedish information retrieval and disambiguation in the query phase. The second purpose was to compare the disambiguation between automatic and manual expansion. We chose a number of topics from the GP_HDINF test collection in Query Performance Analyser …
In this Masters thesis we investigate query expansion using an electronic thesaurus. We formed 30 topics from the library and information science field. For each topic three searches were made in the bibliographic database LISA Library and Information Science Abstracts via CSA …
The purpose of this thesis is to compare five different ranking algorithms for query expansion. The algorithms compared are f4, f4mod, porter, wpq, and emim. This is done using a TREC collection, a selection of topics, and relevance judgements. Relative recall is measured before …
Ett experiment om manuell söksträngsexpansion
The focus of the thesis is an information search technique called manual query expansion, which aims to improve the retrieval per-formance in a search system by adding terms to the search query. The study looks at the query expansions done by LIS students, and the eventual …
… constructed with latent semantic indexing LSI are performing when used for query expansion. There is a well-known problem with synonymy in information retrieval and one solution to this problem is to use a thesaurus. In this thesis thesauri are created automatically to find …
… the morphological analyser SWETWOL was used. Queries were executed in the Query Performance Analyser, QPA, containing the InQuery system. Query terms were selected from 29 topics, all of whom containing at least one compound word. Both the queries and the documents were in …
