Search (2 results, page 1 of 1)

  • × author_ss:"Vakkari, P."
  • × theme_ss:"Benutzerstudien"
  • × type_ss:"a"
  1. Vakkari, P.: How specific thesauri and a general thesaurus cover lay persons' vocabularies concerning health, nutrition and social services 0.00
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    Abstract
    The aim of this study is to compare (1) the semantic structures in lay persons' questions addressed to ask-an-expert service in the fields of health, nutrition and social services, and (2) to which extent lay persons' vocabularies are covered by a general thesaurus and a specific thesaurus in each of these fields. As representation of information needs 50 questions were selected concerning both health and nutrition, and 163 concerning social services. The concepts and their expressions in the questions were identified, and their semantic relations were observed and classified into equivalence, hierarchical and associative relations. The semantic structure of questions varied somewhat between the fields observed. Lay persons' expressions were covered most extensively in health, and least extensively in social services. Specific thesaurus covered more extensively expressions in health (65%) than general thesaurus (42%), whereas in nutrition there was no difference (33% vs. 32%), and in social services general thesaurus (21%) covered expressions somewhat better compared to specific thesaurus (15%). In terms of matching both specific and general thesaurus would provide searchers with reasonable support in term selection for query construction in health, but with limited assistance in nutrition and social services.
    Series
    Advances in knowledge organization; vol.12
    Source
    Paradigms and conceptual systems in knowledge organization: Proceedings of the Eleventh International ISKO conference, Rome, 23-26 February 2010, ed. Claudio Gnoli, Indeks, Frankfurt M
  2. Vakkari, P.; Jones, S.; MacFarlane, A.; Sormunen, E.: Query exhaustivity, relevance feedback and search success in automatic and interactive query expansion (2004) 0.00
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    Abstract
    This study explored how the expression of search facets and relevance feedback (RF) by users was related to search success in interactive and automatic query expansion in the course of the search process. Search success was measured both in the number of relevant documents retrieved, whether identified by users or not. Research design consisted of 26 users searching for four TREC topics in Okapi IR system, half of the searchers using interactive and half automatic query expansion based on RF. The search logs were recorded, and the users filled in questionnaires for each topic concerning various features of searching. The results showed that the exhaustivity of the query was the most significant predictor of search success. Interactive expansion led to better search success than automatic expansion if all retrieved relevant items were counted, but there was no difference between the methods if only those items recognised relevant by users were observed. The analysis showed that the difference was facilitated by the liberal relevance criterion used in TREC not favouring highly relevant documents in evaluation.