Search (333 results, page 2 of 17)

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Abstract

Purpose The effort in addition to relevance is a major factor for satisfaction and utility of the document to the actual user. The purpose of this paper is to propose a method in generating relevance judgments that incorporate effort without human judges' involvement. Then the study determines the variation in system rankings due to low effort relevance judgment in evaluating retrieval systems at different depth of evaluation. Design/methodology/approach Effort-based relevance judgments are generated using a proposed boxplot approach for simple document features, HTML features and readability features. The boxplot approach is a simple yet repeatable approach in classifying documents' effort while ensuring outlier scores do not skew the grading of the entire set of documents. Findings The retrieval systems evaluation using low effort relevance judgments has a stronger influence on shallow depth of evaluation compared to deeper depth. It is proved that difference in the system rankings is due to low effort documents and not the number of relevant documents. Originality/value Hence, it is crucial to evaluate retrieval systems at shallow depth using low effort relevance judgments.

Date

20. 1.2015 18:30:22

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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

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Abstract

Undergraduates were tested to establish how they searched databases, the effectiveness of their searches and their satisfaction with them. The students' cognitive and learning styles were determined by the Lancaster Approaches to Studying Inventory and Riding's Cognitive Styles Analysis tests. There were significant differences in the searching behaviour and the effectiveness of the searches carried out by students with different learning and cognitive styles. Computer-assisted learning (CAL) packages were developed for three departments. The effectiveness of the packages were evaluated. Significant differences were found in the ways students with different learning styles used the packages. Based on the experience gained, guidelines for the teaching of information skills and the production and use of packages were prepared. About 2/3 of the searches had serious weaknesses, indicating a need for effective training. It appears that choice of searching strategies, search effectiveness and use of CAL packages are all affected by the cognitive and learning styles of the searcher. Therefore, students should be made aware of their own styles and, if appropriate, how to adopt more effective strategies

Source

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

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Abstract

Explains briefly what constitutes the imaging process and explains how imaging can be used in information retrieval. Proposes an approach based on the concept of: 'a term is a possible world'; which enables the exploitation of term to term relationships which are estimated using an information theoretic measure. Reports results of an evaluation exercise to compare the performance of imaging retrieval, using possible world semantics, with a benchmark and using the Cranfield 2 document collection to measure precision and recall. Initially, the performance imaging retrieval was seen to be better but statistical analysis proved that the difference was not significant. The problem with imaging retrieval lies in the amount of computations needed to be performed at run time and a later experiement investigated the possibility of reducing this amount. Notes lines of further investigation

Source

Information retrieval: new systems and current research. Proceedings of the 16th Research Colloquium of the British Computer Society Information Retrieval Specialist Group, Drymen, Scotland, 22-23 Mar 94. Ed.: R. Leon

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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

Over the last 4 years, the Information Interaction Laboratory at Rutgers' School of communication, Information and Library Studies has performed a series of investigations concerned with various aspects of people's interactions with advanced information retrieval (IR) systems. We have benn especially concerned with understanding not just what people do, and why, and with what effect, but also with what they would like to do, and how they attempt to accomplish it, and with what difficulties. These investigations have led to some quite interesting conclusions about the nature and structure of people's interactions with information, about support for cooperative human-computer interaction in query reformulation, and about the value of visualization of search results for supporting various forms of interaction with information. In this discussion, I give an overview of the research program and its projects, present representative results from the projects, and discuss some implications of these results for support of subject searching in information retrieval systems

Date

22. 9.1997 19:16:05

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Abstract

Purpose The purpose of this paper is to propose a method to have more accurate results in comparing performance of the paired information retrieval (IR) systems with reference to the current method, which is based on the mean effectiveness scores of the systems across a set of identified topics/queries. Design/methodology/approach Based on the proposed approach, instead of the classic method of using a set of topic scores, the documents level scores are considered as the evaluation unit. These document scores are the defined document's weight, which play the role of the mean average precision (MAP) score of the systems as a significance test's statics. The experiments were conducted using the TREC 9 Web track collection. Findings The p-values generated through the two types of significance tests, namely the Student's t-test and Mann-Whitney show that by using the document level scores as an evaluation unit, the difference between IR systems is more significant compared with utilizing topic scores. Originality/value Utilizing a suitable test collection is a primary prerequisite for IR systems comparative evaluation. However, in addition to reusable test collections, having an accurate statistical testing is a necessity for these evaluations. The findings of this study will assist IR researchers to evaluate their retrieval systems and algorithms more accurately.

Date

20. 1.2015 18:30:22

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Abstract

This paper discusses the role of user-centred evaluations as an essential method for researching interactive information retrieval. It draws mainly on the work carried out during the Clarity Project where different user-centred evaluations were run during the lifecycle of a cross-language information retrieval system. The iterative testing was not only instrumental to the development of a usable system, but it enhanced our knowledge of the potential, impact, and actual use of cross-language information retrieval technology. Indeed the role of the user evaluation was dual: by testing a specific prototype it was possible to gain a micro-view and assess the effectiveness of each component of the complex system; by cumulating the result of all the evaluations (in total 43 people were involved) it was possible to build a macro-view of how cross-language retrieval would impact on users and their tasks. By showing the richness of results that can be acquired, this paper aims at stimulating researchers into considering user-centred evaluations as a flexible, adaptable and comprehensive technique for investigating non-traditional information access systems.

Source

Information processing and management. 44(2008) no.1, S.22-38

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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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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

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Date

27. 2.1999 20:55:22

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Date

27. 2.1999 20:59:22

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Source

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

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Abstract

A summary of the findings of various evaluations of role indicators is given. In general, the results have been negative in that little real evidence for the value of the devices has been presented. The need for roles in various subject fields and in very large systems, is discussed. They can only by justified on purely ecomic grounds - if the added cost involved in their use is offset by substantial reduction in the amount of output screening that must be done by the end user

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Abstract

Reviews the overall results of the TREC experiments in information retrieval, which differed from other information retrieval research projects in that the document collections used in the research were massive, and the groups participating in the collaborative evaluation are among the main organizations in the field. Reviews the findings of TREC, the way in which it operates and the specialist 'tracks' it supports and concentrates on european involvement in TREC, examining the participants and the emergence of European TREC like exercises

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Abstract

This study systematically compares retrievals on 11 topics across five well-known data bases, with MEDLINE's subject indexing as a focus. Each topic was posed by a researcher in the medical behavioral sciences. Each was searches in MEDLINE, EXCERPTA MEDICA, and PSYCHINFO, which permit descriptor searches, and in SCISEARCH and SOCIAL SCISEARCH, which express topics through cited references. Searches on each topic were made with (1) descriptors, (2) cited references, and (3) natural language (a capabiblity common to all five data bases). The researchers who posed the topics judged the results. In every case, the set of records judged relevant was used to to calculate recall, precision, and novelty ratios. Overall, MEDLINE had the highest recall percentage (37%), followed by SSCI (31%). All searches resulted in high precision ratios; novelty ratios of data bases and searches varied widely. Differences in record format among data bases affected the success of the natural language retrievals. Some 445 documents judged relevant were not retrieved from MEDLINE using its descriptors; they were found in MEDLINE through natural language or in an alternative data base. An analysis was performed to examine possible faults in MEDLINE subject indexing as the reason for their nonretrieval. However, no patterns of indexing failure could be seen in those documents subsequently found in MEDLINE through known-item searches. Documents not found in MEDLINE primarily represent failures of coverage - articles were from nonindexed or selectively indexed journals

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Abstract

In an endeavour to compare retrieval performance and periodical overlap in a biological field, the same topic was searched on 5 Table of Contents (ToC) databases and 3 specialised biological databases. Performance was assessed in terms of precision and recall. The ToC databases in general had higher precision in that most material found was relevant. They were less satisfactory in recall where some located fewer than 50% of identified high relevance articles. Subject specific databases had overall better recall but lower precision with many more false drops and items of low relevance occuring. These differences were associated with variations in indexing practice and policy and searching capabilities of the various databases. In a further comparison, it was found that the electronic databases, as a group, identified only 75% of the articles known from independent source to have been published in the field

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Abstract

After introducing types of records, queries and text processing options, the features needed in software for phrase processing are identified and different approaches in current text retrieval research in the Text Retrieval Conference (TREC) projects are enumerated. Then follow eight observations on issues in phrase searching relating both to practice and to research, giving the authors' selection of crucial and controversial issues, supported by 21 references

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Abstract

Reports an evaluation of 3 methods for the expansion of natural language queries in ranked output retrieval systems. The methods are based on term co-occurrence data, on Soundex codes, and on a string similarity measure. Searches for 110 queries in a data base of 26.280 titles and abstracts suggest that there is no significant difference in retrieval effectiveness between any of these methods and unexpanded searches

Theme

Semantisches Umfeld in Indexierung u. Retrieval