Search (70 results, page 1 of 4)

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Date

20.10.2000 12:22:23

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Source

Online. 22(1998) no.3, S.24-26,28

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Abstract

51 subject searches were performed in an online catalog containing about 4,5 million records. Their success was judges in terms of lists of items, known to be relevant to the various topics, compiled by subject specialists (faculty members or authors of articles in specialized encyclopedias). Many of the items known to be relevant were not retrieved, even in very broad searches that sometimes retrieved several hundred records, and very little could be done to make them retrievable within the constraints of present cataloging practice. Librarians should recognize that library catalogs, as now implemented, offer only the most primitive of subject access and should seek to develop different types of subject access tools. - Vgl auch Letter (B.H. Weinberg) in: LTRS 36(1992) S.123-124.

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Source

Journal of information science. 22(1996) no.2, S.79-92

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Abstract

The Initiative for the Evaluation of XML retrieval (INEX) provides a TREC-like platform for evaluating content-oriented XML retrieval systems. Since 2007, INEX has been using a set of precision-recall based metrics for its ad hoc tasks. The authors investigate the reliability and robustness of these focused retrieval measures, and of the INEX pooling method. They explore four specific questions: How reliable are the metrics when assessments are incomplete, or when query sets are small? What is the minimum pool/query-set size that can be used to reliably evaluate systems? Can the INEX collections be used to fairly evaluate "new" systems that did not participate in the pooling process? And, for a fixed amount of assessment effort, would this effort be better spent in thoroughly judging a few queries, or in judging many queries relatively superficially? The authors' findings validate properties of precision-recall-based metrics observed in document retrieval settings. Early precision measures are found to be more error-prone and less stable under incomplete judgments and small topic-set sizes. They also find that system rankings remain largely unaffected even when assessment effort is substantially (but systematically) reduced, and confirm that the INEX collections remain usable when evaluating nonparticipating systems. Finally, they observe that for a fixed amount of effort, judging shallow pools for many queries is better than judging deep pools for a smaller set of queries. However, when judging only a random sample of a pool, it is better to completely judge fewer topics than to partially judge many topics. This result confirms the effectiveness of pooling methods.

Date

22. 1.2011 14:20:56

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Abstract

Purpose - This paper reports the findings of a study designed to explore web searchers' perceptions of the causes of their search failure and success. In particular, it seeks to discover the extent to which the constructs locus of control and attribution theory might provide useful frameworks for understanding searchers' perceptions. Design/methodology/approach - A combination of inductive and deductive approaches were employed. Perceptions of failed and successful searches were derived from the inductive analysis of using open-ended qualitative interviews with a sample of 37 biologists at the University of Sheffield. These perceptions were classified into "internal" and "external" attributions, and the relationships between these categories and "successful" and "failed" searches were analysed deductively to test the extent to which they might be explainable using locus of control and attribution theory interpretive frameworks. Findings - All searchers were readily able to recall "successful" and "unsuccessful" searches. In a large majority of cases (82.4 per cent), they clearly attributed each search to either internal (e.g. ability or effort) or external (e.g. luck or information not being available) factors. The pattern of such relationships was analysed, and mapped onto those that would be predicted by locus of control and attribution theory. The authors conclude that the potential of these theoretical frameworks to illuminate one's understanding of web searching, and associated training, merits further systematic study. Research limitations/implications - The findings are based on a relatively small sample of academic and research staff in a particular subject area. Importantly, also, the study can at best provide a prima facie case for further systematic study since, although the patterns of attribution behaviour accord with those predictable by locus of control and attribution theory, data relating to the predictive elements of these theories (e.g. levels of confidence and achievement) were not available. This issue is discussed, and recommendations made for further work. Originality/value - The findings provide some empirical support for the notion that locus of control and attribution theory might - subject to the limitations noted above - be potentially useful theoretical frameworks for helping us better understand web-based information seeking. If so, they could have implications particularly for better understanding of searchers' motivations, and for the design and development of more effective search training programmes.

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Abstract

Purpose - This paper aims to examine our current knowledge of how searchers perceive and react to the possibility of missing potentially important information whilst searching the web is limited. The study reported here seeks to investigate such perceptions and reactions, and to explore the extent to which Simon's "bounded rationality" theory is useful in illuminating these issues. Design/methodology/approach - Totally 37 academic staff, research staff and research students in three university departments were interviewed about their web searching. The open-ended, semi-structured interviews were inductively analysed. Emergence of the concept of "good enough" searching prompted a further analysis to explore the extent to which the data could be interpreted in terms of Simon's concepts of "bounded rationality" and "satisficing". Findings - The results indicate that the risk of missing potentially important information was a matter of concern to the interviewees. Their estimations of the likely extent and importance of missed information affected decisions by individuals as to when to stop searching - decisions based on very different criteria, which map well onto Simon's concepts. On the basis of the interview data, the authors propose tentative categorizations of perceptions of the risk of missing information including "inconsequential" "tolerable" "damaging" and "disastrous" and search strategies including "perfunctory" "minimalist" "nervous" and "extensive". It is concluded that there is at least a prima facie case for bounded rationality and satisficing being considered as potentially useful concepts in our quest better to understand aspects of human information behaviour. Research limitations/implications - Although the findings are based on a relatively small sample and an exploratory qualitative analysis, it is argued that the study raises a number of interesting questions, and has implications for both the development of theory and practice in the areas of web searching and information literacy. Originality/value - The paper focuses on an aspect of web searching which has not to date been well explored. Whilst research has done much to illuminate searchers' perceptions of what they find on the web, we know relatively little of their perceptions of, and reactions to information that they fail to find. The study reported here provides some tentative models, based on empirical evidence, of these phenomena.

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Source

Online. 22(1998) no.6, S.57-58

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Date

11. 8.2001 16:22:19

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Date

22. 7.2006 18:43:54

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Source

Information retrieval: GI/GMD-Workshop, Darmstadt, 23.-24.6.1991: Proceedings. Ed.: N. Fuhr

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Abstract

One of the major causes of search failures in information retrieval systems is vocabulary mismatch. Presents a solution to the vocabulary problem through 2 strategies known as term suggestion (TS) and term relevance feedback (TRF). In TS, collection specific terms are extracted from the text collection. These terms and their frequencies constitute the keyword database for suggesting terms in response to users' queries. One effect of this term suggestion is that it functions as a dynamic directory if the query is a general term that contains broad meaning. In term relevance feedback, terms extracted from the top ranked documents retrieved from the previous query are shown to users for relevance feedback. In the experiment, interactive TS provides very high precision rates while achieving similar recall rates as n-gram matching. Local TRF achieves improvement in both precision and recall rate in a full text news database and degrades slightly in recall rate in bibliographic databases due to the very limited source of information for feedback. In terms of Rijsbergen's combined measure of recall and precision, both TS and TRF achieve better performance than n-gram matching, which implies that the greater improvement in precision rate compensates the slight degradation in recall rate for TS and TRF

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Content

Enthält die Beiträge: ROBERTSON, S.E.: The methodology of information retrieval experiment; RIJSBERGEN, C.J. van: Retrieval effectiveness; BELKIN, N.: Ineffable concepts in information retrieval; TAGUE, J.M.: The pragmatics of information retrieval experimentation; LANCASTER, F.W.: Evaluation within the environment of an operating information service; BARRACLOUGH, E.D.: Opportunities for testing with online systems; KEEN, M.E.: Laboratory tests of manual systems; ODDY, R.N.: Laboratory tests: automatic systems; HEINE, M.D.: Simulation, and simulation experiments; COOPER, W.S.: Gedanken experimentation: an alternative to traditional system testing?; SPARCK JONES, K.: Actual tests - retrieval system tests; EVANS, L.: An experiment: search strategy variation in SDI profiles; SALTON, G.: The Smart environment for retrieval system evaluation - advantage and problem areas