Search (137 results, page 1 of 7)

  • × theme_ss:"Retrievalstudien"
  1. Agata, T.: ¬A measure for evaluating search engines on the World Wide Web : retrieval test with ESL (Expected Search Length) (1997) 0.03 
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  2. Kantor, P.; Kim, M.H.; Ibraev, U.; Atasoy, K.: Estimating the number of relevant documents in enormous collections (1999) 0.02 
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    Abstract
    In assessing information retrieval systems, it is important to know not only the precision of the retrieved set, but also to compare the number of retrieved relevant items to the total number of relevant items. For large collections, such as the TREC test collections, or the World Wide Web, it is not possible to enumerate the entire set of relevant documents. If the retrieved documents are evaluated, a variant of the statistical "capture-recapture" method can be used to estimate the total number of relevant documents, providing the several retrieval systems used are sufficiently independent. We show that the underlying signal detection model supporting such an analysis can be extended in two ways. First, assuming that there are two distinct performance characteristics (corresponding to the chance of retrieving a relevant, and retrieving a given non-relevant document), we show that if there are three or more independent systems available it is possible to estimate the number of relevant documents without actually having to decide whether each individual document is relevant. We report applications of this 3-system method to the TREC data, leading to the conclusion that the independence assumptions are not satisfied. We then extend the model to a multi-system, multi-problem model, and show that it is possible to include statistical dependencies of all orders in the model, and determine the number of relevant documents for each of the problems in the set. Application to the TREC setting will be presented
  3. Bar-Ilan, J.: ¬The Web as an information source on informetrics? : A content analysis (2000) 0.02 
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    Abstract
    This article addresses the question of whether the Web can serve as an information source for research. Specifically, it analyzes by way of content analysis the Web pages retrieved by the major search engines on a particular date (June 7, 1998), as a result of the query 'informetrics OR informetric'. In 807 out of the 942 retrieved pages, the search terms were mentioned in the context of information science. Over 70% of the pages contained only indirect information on the topic, in the form of hypertext links and bibliographical references without annotation. The bibliographical references extracted from the Web pages were analyzed, and lists of most productive authors, most cited authors, works, and sources were compiled. The list of reference obtained from the Web was also compared to data retrieved from commercial databases. For most cases, the list of references extracted from the Web outperformed the commercial, bibliographic databases. The results of these comparisons indicate that valuable, freely available data is hidden in the Web waiting to be extracted from the millions of Web pages
  4. Lazonder, A.W.; Biemans, H.J.A.; Wopereis, I.G.J.H.: Differences between novice and experienced users in searching information on the World Wide Web (2000) 0.02 
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    Abstract
    Searching for information on the WWW basically comes down to locating an appropriate Web site and to retrieving relevant information from that site. This study examined the effect of a user's WWW experience on both phases of the search process. 35 students from 2 schools for Dutch pre-university education were observed while performing 3 search tasks. The results indicate that subjects with WWW-experience are more proficient in locating Web sites than are novice WWW-users. The observed differences were ascribed to the experts' superior skills in operating Web search engines. However, on tasks that required subjects to locate information on specific Web sites, the performance of experienced and novice users was equivalent - a result that is in line with hypertext research. Based on these findings, implications for training and supporting students in searching for information on the WWW are identified. Finally, the role of the subjects' level of domain expertise is discussed and directions for future research are proposed
  5. Wu, C.-J.: Experiments on using the Dublin Core to reduce the retrieval error ratio (1998) 0.02 
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    Abstract
    In order to test the power of metadata on information retrieval, an experiment was designed and conducted on a group of 7 graduate students using the Dublin Core as the cataloguing metadata. Results show that, on average, the retrieval error rate is only 2.9 per cent for the MES system (http://140.136.85.194), which utilizes the Dublin Core to describe the documents on the World Wide Web, in contrast to 20.7 per cent for the 7 famous search engines including HOTBOT, GAIS, LYCOS, EXCITE, INFOSEEK, YAHOO, and OCTOPUS. The very low error rate indicates that the users can use the information of the Dublin Core to decide whether to retrieve the documents or not
  6. Schabas, A.H.: Postcoordinate retrieval : a comparison of two retrieval languages (1982) 0.02 
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    Abstract
    This article reports on a comparison of the postcoordinate retrieval effectiveness of two indexing languages: LCSH and PRECIS. The effect of augmenting each with title words was also studies. The database for the study was over 15.000 UK MARC records. Users returned 5.326 relevant judgements for citations retrieved for 61 SDI profiles, representing a wide variety of subjects. Results are reported in terms of precision and relative recall. Pure/applied sciences data and social science data were analyzed separately. Cochran's significance tests for ratios were used to interpret the findings. Recall emerged as the more important measure discriminating the behavior of the two languages. Addition of title words was found to improve recall of both indexing languages significantly. A direct relationship was observed between recall and exhaustivity. For the social sciences searches, recalls from PRECIS alone and from PRECIS with title words were significantly higher than those from LCSH alone and from LCSH with title words, respectively. Corresponding comparisons for the pure/applied sciences searches revealed no significant differences
  7. Khan, K.; Locatis, C.: Searching through cyberspace : the effects of link display and link density on information retrieval from hypertext on the World Wide Web (1998) 0.01 
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  8. Griesbaum, J.: Evaluierung hybrider Suchsysteme im WWW (2000) 0.01 
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    Abstract
    Der Ausgangspunkt dieser Arbeit ist die Suchproblematik im World Wide Web. Suchmaschinen sind einerseits unverzichtbar für erfolgreiches Information Retrieval, andererseits wird ihnen eine mäßige Leistungsfähigkeit vorgeworfen. Das Thema dieser Arbeit ist die Untersuchung der Retrievaleffektivität deutschsprachiger Suchmaschinen. Es soll festgestellt werden, welche Retrievaleffektivität Nutzer derzeit erwarten können. Ein Ansatz, um die Retrievaleffektivität von Suchmaschinen zu erhöhen besteht darin, redaktionell von Menschen erstellte und automatisch generierte Suchergebnisse in einer Trefferliste zu vermengen. Ziel dieser Arbeit ist es, die Retrievaleffektivität solcher hybrider Systeme im Vergleich zu rein roboterbasierten Suchmaschinen zu evaluieren. Zunächst werden hierzu die grundlegenden Problembereiche bei der Evaluation von Retrievalsystemen analysiert. In Anlehnung an die von Tague-Sutcliff vorgeschlagene Methodik wird unter Beachtung der webspezifischen Besonderheiten eine mögliche Vorgehensweise erschlossen. Darauf aufbauend wird das konkrete Setting für die Durchführung der Evaluation erarbeitet und ein Retrievaleffektivitätstest bei den Suchmaschinen Lycos.de, AItaVista.de und QualiGo durchgeführt.
  9. Dresel, R.; Hörnig, D.; Kaluza, H.; Peter, A.; Roßmann, A.; Sieber, W.: Evaluation deutscher Web-Suchwerkzeuge : Ein vergleichender Retrievaltest (2001) 0.01 
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    Abstract
    Die deutschen Suchmaschinen, Abacho, Acoon, Fireball und Lycos sowie die Web-Kataloge Web.de und Yahoo! werden einem Qualitätstest nach relativem Recall, Precision und Availability unterzogen. Die Methoden der Retrievaltests werden vorgestellt. Im Durchschnitt werden bei einem Cut-Off-Wert von 25 ein Recall von rund 22%, eine Precision von knapp 19% und eine Verfügbarkeit von 24% erreicht
  10. Ng, K.B.; Loewenstern, D.; Basu, C.; Hirsh, H.; Kantor, P.B.: Data fusion of machine-learning methods for the TREC5 routing tak (and other work) (1997) 0.01 
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    Date
    27. 2.1999 20:59:22
  11. Mansourian, Y.; Ford, N.: Search persistence and failure on the web : a "bounded rationality" and "satisficing" analysis (2007) 0.01 
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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.
  12. Sievert, M.E.; McKinin, E.J.: Why full-text misses some relevant documents : an analysis of documents not retrieved by CCML or MEDIS (1989) 0.01 
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    Abstract
    Searches conducted as part of the MEDLINE/Full-Text Research Project revealed that the full-text data bases of clinical medical journal articles (CCML (Comprehensive Core Medical Library) from BRS Information Technologies, and MEDIS from Mead Data Central) did not retrieve all the relevant citations. An analysis of the data indicated that 204 relevant citations were retrieved only by MEDLINE. A comparison of the strategies used on the full-text data bases with the text of the articles of these 204 citations revealed that 2 reasons contributed to these failure. The searcher often constructed a restrictive strategy which resulted in the loss of relevant documents; and as in other kinds of retrieval, the problems of natural language caused the loss of relevant documents.
    Date
    9. 1.1996 10:22:31
  13. Smithson, S.: Information retrieval evaluation in practice : a case study approach (1994) 0.01 
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    Abstract
    The evaluation of information retrieval systems is an important yet difficult operation. This paper describes an exploratory evaluation study that takes an interpretive approach to evaluation. The longitudinal study examines evaluation through the information-seeking behaviour of 22 case studies of 'real' users. The eclectic approach to data collection produced behavioral data that is compared with relevance judgements and satisfaction ratings. The study demonstrates considerable variations among the cases, among different evaluation measures within the same case, and among the same measures at different stages within a single case. It is argued that those involved in evaluation should be aware of the difficulties, and base any evaluation on a good understanding of the cases in question
  14. Pemberton, J.K.; Ojala, M.; Garman, N.: Head to head : searching the Web versus traditional services (1998) 0.01 
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    Source
    Online. 22(1998) no.3, S.24-26,28
  15. ¬The Eleventh Text Retrieval Conference, TREC 2002 (2003) 0.01 
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    Abstract
    Proceedings of the llth TREC-conference held in Gaithersburg, Maryland (USA), November 19-22, 2002. Aim of the conference was discussion an retrieval and related information-seeking tasks for large test collection. 93 research groups used different techniques, for information retrieval from the same large database. This procedure makes it possible to compare the results. The tasks are: Cross-language searching, filtering, interactive searching, searching for novelty, question answering, searching for video shots, and Web searching.
  16. Behnert, C.; Lewandowski, D.: ¬A framework for designing retrieval effectiveness studies of library information systems using human relevance assessments (2017) 0.01 
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    Abstract
    Purpose This paper demonstrates how to apply traditional information retrieval evaluation methods based on standards from the Text REtrieval Conference (TREC) and web search evaluation to all types of modern library information systems including online public access catalogs, discovery systems, and digital libraries that provide web search features to gather information from heterogeneous sources. Design/methodology/approach We apply conventional procedures from information retrieval evaluation to the library information system context considering the specific characteristics of modern library materials. Findings We introduce a framework consisting of five parts: (1) search queries, (2) search results, (3) assessors, (4) testing, and (5) data analysis. We show how to deal with comparability problems resulting from diverse document types, e.g., electronic articles vs. printed monographs and what issues need to be considered for retrieval tests in the library context. Practical implications The framework can be used as a guideline for conducting retrieval effectiveness studies in the library context. Originality/value Although a considerable amount of research has been done on information retrieval evaluation, and standards for conducting retrieval effectiveness studies do exist, to our knowledge this is the first attempt to provide a systematic framework for evaluating the retrieval effectiveness of twenty-first-century library information systems. We demonstrate which issues must be considered and what decisions must be made by researchers prior to a retrieval test.
  17. Mansourian, Y.; Ford, N.: Web searchers' attributions of success and failure: an empirical study (2007) 0.01 
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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.
  18. Larsen, B.; Ingwersen, P.; Lund, B.: Data fusion according to the principle of polyrepresentation (2009) 0.01 
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    Abstract
    We report data fusion experiments carried out on the four best-performing retrieval models from TREC 5. Three were conceptually/algorithmically very different from one another; one was algorithmically similar to one of the former. The objective of the test was to observe the performance of the 11 logical data fusion combinations compared to the performance of the four individual models and their intermediate fusions when following the principle of polyrepresentation. This principle is based on cognitive IR perspective (Ingwersen & Järvelin, 2005) and implies that each retrieval model is regarded as a representation of a unique interpretation of information retrieval (IR). It predicts that only fusions of very different, but equally good, IR models may outperform each constituent as well as their intermediate fusions. Two kinds of experiments were carried out. One tested restricted fusions, which entails that only the inner disjoint overlap documents between fused models are ranked. The second set of experiments was based on traditional data fusion methods. The experiments involved the 30 TREC 5 topics that contain more than 44 relevant documents. In all tests, the Borda and CombSUM scoring methods were used. Performance was measured by precision and recall, with document cutoff values (DCVs) at 100 and 15 documents, respectively. Results show that restricted fusions made of two, three, or four cognitively/algorithmically very different retrieval models perform significantly better than do the individual models at DCV100. At DCV15, however, the results of polyrepresentative fusion were less predictable. The traditional fusion method based on polyrepresentation principles demonstrates a clear picture of performance at both DCV levels and verifies the polyrepresentation predictions for data fusion in IR. Data fusion improves retrieval performance over their constituent IR models only if the models all are quite conceptually/algorithmically dissimilar and equally and well performing, in that order of importance.
    Date
    22. 3.2009 18:48:28
  19. Voorhees, E.M.; Harman, D.K.: ¬The Text REtrieval Conference (2005) 0.01 
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    Abstract
    Text retrieval technology targets a problem that is all too familiar: finding relevant information in large stores of electronic documents. The problem is an old one, with the first research conference devoted to the subject held in 1958 [11]. Since then the problem has continued to grow as more information is created in electronic form and more people gain electronic access. The advent of the World Wide Web, where anyone can publish so everyone must search, is a graphic illustration of the need for effective retrieval technology. The Text REtrieval Conference (TREC) is a workshop series designed to build the infrastructure necessary for the large-scale evaluation of text retrieval technology, thereby accelerating its transfer into the commercial sector. The series is sponsored by the U.S. National Institute of Standards and Technology (NIST) and the U.S. Department of Defense. At the time of this writing, there have been twelve TREC workshops and preparations for the thirteenth workshop are under way. Participants in the workshops have been drawn from the academic, commercial, and government sectors, and have included representatives from more than twenty different countries. These collective efforts have accomplished a great deal: a variety of large test collections have been built for both traditional ad hoc retrieval and related tasks such as cross-language retrieval, speech retrieval, and question answering; retrieval effectiveness has approximately doubled; and many commercial retrieval systems now contain technology first developed in TREC.
  20. Díaz, A.; García, A.; Gervás, P.: User-centred versus system-centred evaluation of a personalization system (2008) 0.01 
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    Abstract
    Some of the most popular measures to evaluate information filtering systems are usually independent of the users because they are based in relevance judgments obtained from experts. On the other hand, the user-centred evaluation allows showing the different impressions that the users have perceived about the system running. This work is focused on discussing the problem of user-centred versus system-centred evaluation of a Web content personalization system where the personalization is based on a user model that stores long term (section, categories and keywords) and short term interests (adapted from user provided feedback). The user-centred evaluation is based on questionnaires filled in by the users before and after using the system and the system-centred evaluation is based on the comparison between ranking of documents, obtained from the application of a multi-tier selection process, and binary relevance judgments collected previously from real users. The user-centred and system-centred evaluations performed with 106 users during 14 working days have provided valuable data concerning the behaviour of the users with respect to issues such as document relevance or the relative importance attributed to different ways of personalization. The results obtained shows general satisfaction on both the personalization processes (selection, adaptation and presentation) and the system as a whole.

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  • s 9
  • m 6
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