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Background: Search filters have been developed in MEDLINE and EMBASE to help overcome the challenges of searching electronic databases for information on adverse effects. However, little evaluation of their effectiveness has been carried out. Objectives: To measure the sensitivity and precision of available adverse effects search filters in MEDLINE and EMBASE. Methods: A case study systematic review of fracture related adverse effects associated with the use of thiazolidinediones was used. Twelve MEDLINE search strategies and three EMBASE search strategies were tested. Results: Nineteen relevant references from MEDLINE and 24 from EMBASE were included in the review. Four search filters in MEDLINE achieved high sensitivity (95 or 100%) with an improved level of precision from searches without any adverse effects filter. High precision in MEDLINE could also be achieved (up to 53%) using search filters that rely on Medical Subject Headings. No search filter in EMBASE achieved high precision (all were under 5%) and the highest sensitivity in EMBASE was 83%. Conclusions: Adverse effects search filters appear to be effective in MEDLINE for achieving either high sensitivity or high precision. Search filters in EMBASE, however, do not appear as effective, particularly in improving precision. 相似文献
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Bronson RJ 《Medical reference services quarterly》1994,13(1):73-80
Locating notes about MeSH subheadings can be one of the most difficult aspects of MEDLINE searching. When used with Medical Subject Headings (MeSH), subheadings serve to limit or define the focus of a heading. National Library of Medicine (NLM) indexers, staff members who enter the MeSH indexing into the database, use subheadings freely. They do follow indexing conventions and savy searchers need to be aware of how to obtain basic subheading information to assist in search formulation. There are a number of methods which may be used in order to view subheading use notes. This column will provide an overview of some alternatives to locating such information. 相似文献
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Through casual observations, formal consultations, and educational sessions, the authors have identified various indexing features of the National Library of Medicine's Medical Subject Headings (MeSH) that pose challenges to end users while attempting to obtain relevant retrieval when searching MEDLINE. These problematic features include the use of Explodes, Tree structures, subheadings, Text Word vs. subject heading searching, and central concept searching. End-user search software is becoming more sophisticated with an increasing number of choices offered for search strategy formulation. Methods of instruction to orient the end user to these systems will also have to become more detailed. A review of the literature, that discusses end-user problems with using MEDLINE and MeSH, is included. 相似文献
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《Medical reference services quarterly》2013,32(3):29-46
Through casual observations, formal consultations, and educational sessions, the authors have identified various indexing features of the National Library of Medicine's Medical Subject Headings (MeSH) that pose challenges to end users while attempting to obtain relevant retrieval when searching MEDUNE. These problematic features include the use of Explodes, Tree structures, subheadings, Text Word vs. subject heading searching, and central concept searching. End-user search software is becoming more sophisticated with an increasing number of choices offered for search strategy fomalation. Methods of instruction to orient the end user to these systems will also have to become more detailed. A review of the literature, that discusses end-user problems with using MEDLINE and MeSH, is included. 相似文献
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Indexing consistency in MEDLINE 总被引：3，自引：0，他引：3
The quality of indexing of periodicals in a bibliographic data base cannot be measured directly, as there is no one "correct" way to index an item. However, consistency can be used to measure the reliability of indexing. To measure consistency in MEDLINE, 760 twice-indexed articles from 42 periodical issues were identified in the data base, and their indexing compared. Consistency, expressed as a percentage, was measured using Hooper's equation. Overall, checktags had the highest consistency. Medical Subject Headings (MeSH) and subheadings were applied more consistently to central concepts than to peripheral points. When subheadings were added to a main heading, consistency was lowered. "Floating" subheadings were more consistent than were attached subheadings. Indexing consistency was not affected by journal indexing priority, language, or length of the article. Terms from MeSH Tree Structure categories A, B, and D appeared more often than expected in the high-consistency articles; whereas terms from categories E, F, H, and N appeared more often than expected in the low-consistency articles. MEDLINE, with its excellent controlled vocabulary, exemplary quality control, and highly trained indexers, probably represents the state of the art in manually indexed data bases. 相似文献
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N S Hewison 《Bulletin of the Medical Library Association》1989,77(4):332-336
The emergence of CD-ROM (compact disc/read-only memory) versions of the MEDLINE database requires experienced MEDLINE searchers to examine assumptions about searching MEDLINE, since some expectations may not be fulfilled by this new technology. When applied to a particular CD-ROM MEDLINE product, the evaluation procedure involves testing assumptions concerning database contents; mechanics of searching; display, print, and download capabilities; and user-friendly features. The extent to which a CD-ROM product preserves and exploits important MEDLINE strengths should be assessed, e.g., the MeSH controlled vocabulary, the designation of major and minor MeSH emphasis, and the use of subheadings. Search software characteristics that affect ease of searching and quality of results also need to be examined, e.g., the ability to truncate search terms and the order of precedence in which Boolean operators are evaluated. A checklist to assist in the evaluation process is presented, including search examples for use in testing search functions. 相似文献
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This study analyzes the search behavior of end users who had taken a class in searching MEDLINE on the National Library of Medicine's MEDLARS system. Of the class alumni, 58% obtained passwords. Most of these were still conducting their own searches twelve to eighteen months later. Telephone interviews and search observations indicated that these end users were satisfied with their results and felt they had mastered the basic mechanics of searching. However, appropriate use of explodes and subheadings, as well as locating appropriate search terms, still presented difficulties for them. Further training in these areas may be required. 相似文献
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MEDTUTOR is an interactive, microcomputer-based training package designed to teach medical and health professionals, as well as librarians and information specialists, how to use MEDLINE effectively. The objective of MEDTUTOR is to provide a comprehensive package for teaching the various commands and search techniques required for utilizing the MEDLINE database through the MEDLARS system. MEDTUTOR's menu-driven design allows novice users to learn about the content and use of MEDLINE, such as author searching, text word searching, MeSH indexing, etc., at their own pace and with considerable program feedback. In addition, MEDTUTOR provides the skilled searcher with a way to reinforce or recall previously-learned search techniques without incurring online charges. MEDTUTOR may be used in place of formal training, as a precursor to or as a refresher following formal training, or for review of a particular concept. It provides inexpensive and easily accessible instruction for searching MEDLINE. 相似文献
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Steve Mcdonald Libby Taylor Clive Adams 《Health information and libraries journal》1999,16(3):151-156
Journal coverage is one factor that affects the retrieval of relevant information from bibliographic databases. The aims of this study were to investigate the coverage of databases for psychiatry journals, and to assess the overlap between databases. Psychiatry journals were identified using Ulrich’s International Periodicals Directory and then analysed to see which bibliographic databases indexed the most journals. A total of 213 abstracting and indexing services were listed as indexing at least one of the 977 psychiatry journals identified. The four most frequently cited databases (PsycLIT, EMBASE, BIOSIS and MEDLINE) indexed 506 (52%) of the psychiatry journals. Of these 506 journals, PsycLIT indexed 367 (73%), EMBASE 337 (67%), BIOSIS 243 (48%) and MEDLINE 236 (47%). Combining the databases with the highest yields (PsycLIT and EMBASE) increased the number of journals indexed to 461 (91%). The four databases combined accounted for 90% of all psychiatry journals found to be indexed by at least one abstracting and indexing service. More than 400 journals were not indexed at all. Variations in the overlap between PsycLIT, EMBASE, BIOSIS and MEDLINE, and the high proportion (35%) of journals indexed in only one of these four databases emphasize the importance of searching more than one or even two databases to ensure optimal coverage of the literature. 相似文献
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With so many options available for searching MEDLINE on the World Wide Web or as a component of an online service, evaluation criteria are suggested as a means of assisting librarians in determining the positive and negative aspects of alternative MEDLINE sites. A set of searches was utilized to systematically compare MEDLINE sites. Sites evaluated included Avicenna, America Online, HealthGate, PubMed, Medscape, and Physicians' Online. Some features used to evaluate these sites were: default fields; operators (default); access to MeSH; subheadings; stop words protected in MeSH; truncation; and stemming. This article will describe the group process used to arrive at the evaluation criteria, as well as some general conclusions which will help librarians in directing their users to a particular MEDLINE site. 相似文献
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The purpose of this research was to determine which of three databases, CINAHL, EMBASE or MEDLINE, should be accessed when researching nursing topics. The three databases were searched for citations on topics selected by three nurse researchers and the results were compared. For the search of nursing care literature on a medical condition, it was helpful to search both CINAHL and MEDLINE. CINAHL provided the majority of relevant articles for the second search, on computers and privacy, but inclusion of MEDLINE and EMBASE enhanced retrieval somewhat. The search on substance abuse in pregnancy, not restricted to nursing literature, retrieved better results when searching both MEDLINE and EMBASE. Due to the nature and distribution of the nursing literature, it is especially important for the searcher to understand and respond to the focus of the researcher. 相似文献
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Towards enhancing retrieval effectiveness of search engines for diacritisized Arabic documents 总被引：1，自引：1，他引：0
Bassam H. Hammo 《Information Retrieval》2009,12(3):300-323
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Background: Search filters can potentially improve the efficiency of searches involving electronic databases such as medline and embase . Although search filters have been developed for identifying records that contain adverse effects data, little is known about the sensitivity of such filters. Objectives: This study measured the sensitivity of using available adverse effects filters to retrieve papers with adverse effects data. Methods: A total of 233 included studies from 26 systematic reviews of adverse effects were used for analysis. Search filters from medline and embase were tested for their sensitivity in retrieving the records included in these reviews. In addition, the sensitivity of each individual search term used in at least one search filter was measured. Results: Subheadings proved the most useful search terms in both medline and embase . No indexing terms in medline achieved over 12% sensitivity. The sensitivity of published search filters varied in medline from 3% to 93% and in embase from 57% to 97%. Whether this level of sensitivity is acceptable will be dependent on the purpose of the search. Conclusions: Although no adverse effects search filter captured all the relevant records, high sensitivity could be achieved. Search filters may therefore be useful in retrieving adverse effects data. 相似文献
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McDonald S 《Health information and libraries journal》2002,19(1):14-20
Introduction: Locating reports of trials from journals not indexed in the major databases presents difficulties to systematic reviewers, and may be a factor in improving the reliability of the reviews. Objectives: To identify and make available reports of controlled trials from the Australasian Medical Index (AMI). To measure the quality of indexing of trials in AMI. Methods: Using a highly sensitive search strategy consisting of methodology indexing and free‐text terms, records from AMI were read for reports of controlled trials. Trials meeting the criteria were submitted for inclusion in The Cochrane Controlled Trials Register (CCTR) and assessed for the quality of their indexing. Results: 3621 records were downloaded, of which 512 were identified as reports of controlled trials (317 RCTs; 195 CCTs) and submitted to CCTR. The precision of methodology indexing terms was 60%, but sensitivity just 18%. The quality of indexing of trials was generally poor with only 50 tagged with the RCT/CCT publication type term. 453 reports (88%) were not previously available in CCTR. Conclusions: The large proportion of trials found to be unique to the AMI database increases the pool of studies available to systematic reviewers, and helps ensure CCTR remains the most comprehensive source of trials. 相似文献
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In this paper, which treats Swedish full text retrieval, the problem of morphological variation of query terms in the document database is studied. The Swedish CLEF 2003 test collection was used, and the effects of combination of indexing strategies with query terms on retrieval effectiveness were studied. Four of the seven tested combinations involved indexing strategies that used normalization, a form of conflation. All of these four combinations employed compound splitting, both during indexing and at query phase. SWETWOL, a morphological analyzer for the Swedish language, was used for normalization and compound splitting. A fifth combination used stemming, while a sixth attempted to group related terms by right hand truncation of query terms. The truncation was performed by a search expert. These six combinations were compared to each other and to a baseline combination, where no attempt was made to counteract the problem of morphological variation of query terms in the document database. Both the truncation combination, the four combinations based on normalization and the stemming combination outperformed the baseline. Truncation had the best performance. The main conclusion of the paper is that truncation, normalization and stemming enhanced retrieval effectiveness in comparison to the baseline. Further, normalization and stemming were not far below truncation. 相似文献
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Do published search filters to identify diagnostic test accuracy studies perform adequately? 总被引：1，自引：0，他引：1
OBJECTIVES: To assess the performance of published search filters in finding diagnostic test accuracy studies. METHODS: Diagnostic test accuracy search filters were identified by searching medline, our own files and by requesting unpublished filters from colleagues. We applied the filters to a case study review of diagnostic test accuracy studies for urinary tract infections (UTI) in young children. The included studies with records in medline formed the gold standard. The performance of the filters in finding those gold standard records was assessed. RESULTS: We identified twenty-three diagnostic test accuracy search filters for use with medline. The case study systematic review of UTI included 179 studies of diagnostic test accuracy, of which 160 were available in medline. The filters showed a wide range of sensitivities (range: 20.6% to 86.9%) and precision (range: 1% to 9.4%). CONCLUSIONS: Our results broadly support those reported in two other studies. The search filters tested do not offer an adequate trade-off between sensitivity and precision to be used to identify studies for systematic reviews. However, there are methods available to explore whether search filters are viable based on an objective statistical analysis of the text and indexing used in records. 相似文献
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Finding useful information from large multimodal document collections such as the WWW without encountering numerous false positives poses a challenge to multimedia information retrieval systems (MMIR). This research addresses the problem of finding pictures. The fact that images do not appear in isolation, but rather with accompanying, collateral text is exploited. Taken independently, existing techniques for picture retrieval using (i) text-based and (ii) image-based methods have several limitations. This research presents a general model for multimodal information retrieval that addresses the following issues: (i) users' information need, (ii) expressing information need through composite, multimodal queries, and (iii) determining the most appropriate weighted combination of indexing techniques in order to best satisfy information need. A machine learning approach is proposed for the latter. The focus is on improving precision and recall in a MMIR system by optimally combining text and image similarity. Experiments are presented which demonstrate the utility of individual indexing systems in improving overall average precision. 相似文献