Diese Datenbank enthält über 40.000 Dokumente zu Themen aus den Bereichen Formalerschließung – Inhaltserschließung – Information Retrieval.
© 2015 W. Gödert, TH Köln, Institut für Informationswissenschaft / Powered by litecat, BIS Oldenburg (Stand: 04. Juni 2021)
1Crouch, C.J. ; Crouch, D.B. ; Chen, Q. ; Holtz, S.J.: Improving the retrieval effectiveness of very short queries.
In: Information processing and management. 38(2002) no.1, S.1-36.
Abstract: This paper describes an automatic approach designed to improve the retrieval effectiveness of very short queries such as those used in web searching. The method is based on the observation that stemming, which is designed to maximize recall, often results in depressed precision. Our approach is based on pseudo-feedback and attempts to increase the number of relevant documents in the pseudo-relevant set by reranking those documents based on the presence of unstemmed query terms in the document text. The original experiments underlying this work were carried out using Smart 11.0 and the lnc.ltc weighting scheme on three sets of documents from the TREC collection with corresponding TREC (title only) topics as queries. (The average length of these queries after stoplisting ranges from 2.4 to 4.5 terms.) Results, evaluated in terms of P@20 and non-interpolated average precision, showed clearly that pseudo-feedback (PF) based on this approach was effective in increasing the number of relevant documents in the top ranks. Subsequent experiments, performed on the same data sets using Smart 13.0 and the improved Lnu.ltu weighting scheme, indicate that these results hold up even over the much higher baseline provided by the new weights. Query drift analysis presents a more detailed picture of the improvements produced by this process.
2Crouch, C.J.: ¬An approach to the automatic construction of global thesauri.
In: Information processing and management. 26(1990), no.5, S.629-640.
Abstract: The benefits of a well constructed thesaurus to an information retrieval system have long been recognised by both researchers and practitioners in the field. Examines both early and current approaches to automatic thesaurus construction and describes an approach to the automatic generation of global thesauri based on the term discrimination value model of Salton Yang, and Yu and on an appropriate clustering algorithm. This method has been implemented and applied to 2 document collections. Preliminary results indicate that this method, which produces improvements in retrieval performance in excess of 10 and 15% in the test collections, is viable and worthy of continued investigation.
Themenfeld: Konzeption und Anwendung des Prinzips Thesaurus