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1.
Hierarchically structured thesauri--including MeSH--were studied to test the assumption of an inverse relationship between term specificity and the number of postings in online databases. It was suggested that this assumption holds only for peripheral terms and that the opposite is true for the central terms of a discipline. The Environment tree structure of MeSH was used to test the "peripheral" hypothesis, which was supported at a .05 level of significance, but the scattergram on the Endocrine Diseases tree, which was run to test the "central" hypothesis, had an even better level, .02. The commonly held belief that specific terms are added to a thesaurus when more general ones get too many postings was also tested. The relationship between specificity and dates was supported in MeSH (.015). The corollary--that terms with later dates have fewer postings--was supported at a .001 level of significance. The results for MeSH were much more significant than for other hierarchically structured thesauri, which indicates that thesaurus development at NLM involves interaction with MEDLINE to preclude an excessive number of postings to any one term. 相似文献
2.
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
3.
Lora V. Gault Mary Shultz Kathy J. Davies 《Journal of the Medical Library Association》2002,90(2):173-180
Objectives: This study compared the mapping of natural language patron terms to the Medical Subject Headings (MeSH) across six MeSH interfaces for the MEDLINE database.Methods: Test data were obtained from search requests submitted by patrons to the Library of the Health Sciences, University of Illinois at Chicago, over a nine-month period. Search request statements were parsed into separate terms or phrases. Using print sources from the National Library of Medicine, Each parsed patron term was assigned corresponding MeSH terms. Each patron term was entered into each of the selected interfaces to determine how effectively they mapped to MeSH. Data were collected for mapping success, accessibility of MeSH term within mapped list, and total number of MeSH choices within each list.Results: The selected MEDLINE interfaces do not map the same patron term in the same way, nor do they consistently lead to what is considered the appropriate MeSH term.Conclusions: If searchers utilize the MEDLINE database to its fullest potential by mapping to MeSH, the results of the mapping will vary between interfaces. This variance may ultimately impact the search results. These differences should be considered when choosing a MEDLINE interface and when instructing end users. 相似文献
4.
Medical Subject Headings and medical terminology: an analysis of terminology used in hospital charts
Terminology used by health professionals in everyday written discourse was compared with terminology in a standardized medical vocabulary, the Medical Subject Headings (MeSH). Fifty written hospital charts were selected at random and analyzed by a computer program that identified MeSH terms in the charts. The charts were analyzed against two related MeSH vocabularies--one containing MeSH terms and one containing both MeSH terms and backwards cross-reference terms. When small words such as articles and prepositions were disregarded, approximately 50% of the words in a medical chart were found to be MeSH-related terminology. In addition, about 40% of MeSH-related words in the charts were either MeSH terms or backwards cross-reference terms. 相似文献
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6.
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
7.
Objective: To determine whether information retrieval might be enhanced by making each component of a structured abstract a separately searchable field. Design: Parallel searches on records arranged so that each abstract could either be searched in its entirety or as a collection of structured fields. Subjects: Records about cardiovascular disease downloaded from MEDLINE and tested against clinical questions derived from a concurrent survey of CD-ROM use in three health science libraries. Intervention: The investigators identified terms used to structure abstracts on MEDLINE and imported the abstracts into an Idealist database prior to searching using keywords from clinical questions. Measurements and main results: recall and precision rates are given for each question in the ‘structured’ and the ‘unstructured’ set of records. Conclusions: Use of structured, rather than unstructured, abstracts improves precision at the ex-pense of recall and places heavier demands upon the searcher’s skill in choosing the correct fields within the abstract to search. Further investigation requires more accurate simulation of MEDLINE software that utilizes features such as MeSH terms, explode, facilities and delimiters. 相似文献
8.
This paper investigates the effectiveness of using MeSH® in PubMed through its automatic query expansion process: Automatic Term Mapping (ATM). We run Boolean searches based on a collection of 55 topics and about 160,000 MEDLINE® citations used in the 2006 and 2007 TREC Genomics Tracks. For each topic, we first automatically construct a query by selecting keywords from the question. Next, each query is expanded by ATM, which assigns different search tags to terms in the query. Three search tags: [MeSH Terms], [Text Words], and [All Fields] are chosen to be studied after expansion because they all make use of the MeSH field of indexed MEDLINE citations. Furthermore, we characterize the two different mechanisms by which the MeSH field is used. Retrieval results using MeSH after expansion are compared to those solely based on the words in MEDLINE title and abstracts. The aggregate retrieval performance is assessed using both F-measure and mean rank precision. Experimental results suggest that query expansion using MeSH in PubMed can generally improve retrieval performance, but the improvement may not affect end PubMed users in realistic situations. 相似文献
9.
Jane Harrison 《Health information and libraries journal》1997,14(1):33-42
Thepractice of evidence-based health care requires that information on methodology be identifiedfrom databases such as MEDLINE. Up until this year there have been no designated medicalsubject headings (MeSH) for evidence-based health care. ‘EVIDENCE-BASEDMEDICINE’ appears as a MeSH term from 1997. The absence of designated MeSH forthis concept prior to 1997 provides a challenge to the searcher. This paper describes the creationof a MEDLINE search strategy to retrieve articles on the methods of evidence-based health carepublished prior to the introduction of the new term, where an optimal combination of free-textand MeSH terms is required to identify relevant material. The study examines both free-text andsubject heading searching and attempts an optimal balance of sensitivity and specificity. It beginsby examining separate free-text and subject heading searches. Sensitivity of the subject headingsearch was 33% and specificity 80%, while the free-text search produced asensitivity of 50% and a specificity of 67%. The final strategy, combining bothapproaches, was more successful with sensitivity reaching between 82 and 90% andspecificity 83%. It is therefore possible to devise a search strategy to retrieve articles on themethods of evidence-based health care with relatively successful rates of sensitivity andspecificity. The limitations of MEDLINE, however, necessitate the use of additional approachesin identifying articles on the methods of evidence-based health care. 相似文献
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11.
Flor P Jakobsson A Mogset I Taylor S Aasen SE 《Health information and libraries journal》2001,18(1):10-19
Nursing and allied health libraries at educational institutions in Norway have generally indexed their book collections with uncontrolled terms. With the reorganization of higher education in 1994, the majority of these libraries joined BIBSYS, which is a joint library system for higher education and research in Norway. This has led to chaos when searching the joint catalogue for literature on nursing and related fields. A term such as 'behaviour problems' may have up to five synonyms. In an attempt to improve the quality of searching the health literature, BIBSYS appointed a working group in the Spring of 1999 to find a suitable controlled vocabulary for this subject area, and to see how this vocabulary could be integrated into BIBSYS. The group presented its recommendations in October 1999. The report has been well received by the BIBSYS Board and by user groups. There are no Norwegian vocabularies that are suitable for use in nursing and allied health, therefore it will be necessary to translate and combine existing thesauri. The group has looked at the Nordic Multilingual Thesaurus on Health Promotion, the Swedish Spriline Thesaurus, MeSH (Medical Subject Headings) and CINAHL Subject Heading List. Other relevant thesauri are AMED/CATS Thesaurus, Bioethics Thesaurus (Bioethicsline) and the RCN thesaurus. The group recommends the development of a Norwegian thesaurus based on a translation of parts of MeSH and CINAHL Subject Heading List. 相似文献
12.
Applications of informatics in veterinary medicine 总被引：3，自引：0，他引：3
This study used the peer-reviewed biomedical literature to define the veterinary informatics knowledgebase and associated subspecialties, and assesses the level of activity in the field over the thirty-year period from 1966 through 1995. Grateful Med was used to search the MEDLINE bibliographic database for articles that shared one or more Medical Subject Headings (MeSH) keywords from the veterinary and medical informatics subject headings. Each of ninety-five MeSH medical informatics terms was assigned to one of twelve veterinary informatics subspecialties. The number of articles retrieved by each MeSH keyword and subspecialty was calculated. A total of 611 articles were retrieved, representing the contributions of 1,338 authors published in 153 journals. The field experienced slow growth over the twenty-year period from 1966 through 1985. In the following decade, the cumulative number of veterinary informatics articles almost tripled and the percentage of veterinary-related articles that included an informatics component increased almost two-and-one-half fold. Despite this recent growth, the number of veterinary-related articles with an informatics component has never exceeded 1% of either the veterinary or medical informatics literature over the past thirty years, and representation of veterinary subspecialties in the literature varied widely. 相似文献
13.
近十年国外对中草药研究的关注点——基于高频主题词的共现聚类分析 总被引：1，自引：0，他引：1
目的:调查国外作者发表的中草药研究文献, 分析国外作者对中草药研究的关注点.方法:对PubMed数据库中近10年由国外作者发表的有关中草药的文献进行主题词共现聚类分析, 下载这些文献的主题词并统计主题词出现的频次,截取高频主题词,形成主题词共现矩阵,对矩阵做聚类.通过分析各类的文献内容,得到该主题的研究热点.结果:共检出国外作者发表的论文2 609篇,出现频次超过20次的主题词为43个,聚类得到5个研究热点.结论:①中药抗炎免疫药理、植物型抗肿瘤药物药理、中药抗氧化作用药理以及中药制剂作为神经保护药的药理学研究、黄酮类化合物和生物碱类的药理学研究是中草药药理学研究的关注点;②糖尿病、哮喘等疾病是国外进行中草药治疗应用研究的热点病种;③含马兜铃酸中药的肾脏毒性研究和中草药引起中毒性肝炎的研究是中草药副作用研究的热点;④植物型抗肿瘤药物用于治疗前列腺癌的研究曾受到国外研究人员极大关注;⑤人参属等药用植物的化学成分和人参皂苷药理活性研究受到关注. 相似文献
14.
Objective:This study compares two maps of biomedical sciences using Medical Subject Headings (MeSH) term co-assignments versus MeSH terms of citing/cited articles and reveals similarities and differences between the two approaches.Methods:MeSH terms assigned to 397,475 journal articles published in 2015, as well as their 4,632,992 cited references, were retrieved from Web of Science and MEDLINE databases, respectively, which formed over 7 million MeSH co-assignments and nearly 18 million direct citation pairs. We generated six network visualizations of biomedical science at three levels using Gephi software based on these MeSH co-assignments and citation pairs.Results:The MeSH co-assignment map contained more nodes and edges, as MeSH co-assignments cover all medical topics discussed in articles. By contrast, the MeSH citation map contained fewer but larger nodes and wider edges, as citation links indicate connections to two similar medical topics.Conclusion:These two types of maps emphasize different aspects of biomedical sciences, with MeSH co-assignment maps focusing on the relationship between topics in different categories and MeSH direct citation maps providing insights into relationships between topics in the same or similar category. 相似文献
15.
A M Cain 《Bulletin of the Medical Library Association》1969,57(3):250-259
This paper describes the construction of a synonym thesaurus or entry vocabulary for the SUNY Biomedical Communication Network, which will permit the user greater ease of access to the MeSH-indexed material without previously consulting a printed list of indexing terms. In order to discover the actual terminology used by a researcher, words were extracted from titles of articles appearing in Index Medicus, and compared with the subject heading under which they appeared. As well as strict synonyms, grammatical variants were also included. Work is continuing on relating other indexing vocabularies, such as Excerpta Medica and Current Medical Terminology, used in the biomedical world to MeSH terms. 相似文献
16.
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
17.
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
18.
W Moll 《Bulletin of the Medical Library Association》1971,59(3):458-462
The paper reviews the highlights of a four-week trial period (November 19-December 18, 1970) during which the Medical Library of the University of Virginia experimented with a new remote-access bibliographical control and retrieval system via its TWX machine. The system, called AIM-TWX, was sponsored by the Lister Hill National Center for Biomedical Communications and utilizes a timeshared IBM 360/67 computer in Santa Monica, California. Citations from 109 clinically-oriented journals from 1966 to date, including those currently included in the Abridged Index Medicus, may be retrieved either on- or off-line.Various aspects of this service are described, including problems of staffing, training, and record keeping, as well as the role of the MeSH vocabulary which is the principle "language" of the man-computer dialog.The statistical results indicated that the system was used for approximately 200 minutes on nineteen days and that an average of sixteen searches were run on any given day, or about 4.6 searches per hour of use. In spite of an inexperienced staff who had little knowledge of the MeSH vocabulary and whose training schedule was limited to one four-hour session, the experiment was highly successful in terms of searches and citations.At the end of the period, 298 searches had been run for 114 requestors, and 5,343 citations had been produced. Only fifty-five searches yielded no citations. The experiment generated a great deal of excitement and interest among the staff of the Library and of the Medical Center. Moreover, a large number of medical practitioners in large and small communities of Virginia participated in this experiment, indicating that there exists a great demand for this type of literature searching which AIM-TWX is able to provide with great rapidity. 相似文献
19.
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
20.
Latent Semantic Indexing (LSI) is a popular information retrieval model for concept-based searching. As with many vector space IR models, LSI requires an existing term-document association structure such as a term-by-document matrix. The term-by-document matrix, constructed during document parsing, can only capture weighted vocabulary occurrence patterns in the documents. However, for many knowledge domains there are pre-existing semantic structures that could be used to organize and categorize information. The goals of this study are (i) to demonstrate how such semantic structures can be automatically incorporated into the LSI vector space model, and (ii) to measure the effect of these structures on query matching performance. The new approach, referred to as Knowledge-Enhanced LSI, is applied to documents in the OHSUMED medical abstracts collection using the semantic structures provided by the UMLS Semantic Network and MeSH. Results based on precision-recall data (11-point average precision values) indicate that a MeSH-enhanced search index is capable of delivering noticeable incremental performance gain (as much as 35%) over the original LSI for modest constraints on precision. This performance gain is achieved by replacing the original query with the MeSH heading extracted from the query text via regular expression matches. 相似文献