Sökning: "återvinningseffektivitet"

Visar resultat 16 - 18 av 18 uppsatser innehållade ordet återvinningseffektivitet.

1. 16. En studie av evalueringar av webbaserade söktjänsters återvinningseffektivitet

   Magister-uppsats, Högskolan i Borås/Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan

   Författare :John Carlsson; [2003]
   Nyckelord :library and information science; biblioteks- och informationsvetenskap;

   Sammanfattning : The aim of this thesis is to describe and critically investigate eight different evaluations of the retrieval effectiveness of webbased search engines. The questions to be answered in this investigation are: - What kind of relevance judgements have been used? - Which criteria have been used when judging the relevance of a document? - Which measures have been used? - How many queries have been used? - How were the queries constructed? - What document cut-off value has been used? - Has hypothes testing been applied? - What kind of webbased search engines have been included in the evaluations? The study showed that although the evaluations investigate the same phenomena, they are very different from each other in certain aspects. LÄS MER

3. 17. En komparativ studie av fem rankningsalgoritmer för query expansion

   Magister-uppsats, Högskolan i Borås/Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan

   Författare :Johan Eklund; Anders Stenström; [2002]
   Nyckelord :query expansion; ir-system; återvinningseffektivitet; rankningsalgoritmer; testkollektioner;

   Sammanfattning : 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 and after the expansion of the query. LÄS MER

4. 18. Passage Retrieval : en litteraturstudie av ett forskningsområde inom information retrieval

   Magister-uppsats, Högskolan i Borås/Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan

   Författare :Mattias Åkesson; [2000]
   Nyckelord :information retrieval; passage retrieval; fulltextåtervinning; textstruktur; återvinningseffektivitet;

   Sammanfattning : The aim of this thesis is to describe passage retrieval (PR), with basis in results from various empirical experiments, and to critically investigate different approaches in PR. The main questions to be answered in the thesis are: (1) What characterizes PR? (2) What approaches have been proposed? (3) How well do the approaches work in experimental information retrieval (IR)? PR is a research topic in information retrieval, which instead of retrieving the fulltext of documents, that can lead to information overload for the user, tries to retrieve the most relevant passages in the documents. LÄS MER