共查询到20条相似文献，搜索用时 31 毫秒
1.
Google Scholar,Web of Science,and Scopus: A systematic comparison of citations in 252 subject categories 总被引：1，自引：0，他引：1
Alberto Martín-Martín Enrique Orduna-Malea Mike Thelwall Emilio Delgado López-Cózar 《Journal of Informetrics》2018,12(4):1160-1177
Despite citation counts from Google Scholar (GS), Web of Science (WoS), and Scopus being widely consulted by researchers and sometimes used in research evaluations, there is no recent or systematic evidence about the differences between them. In response, this paper investigates 2,448,055 citations to 2299 English-language highly-cited documents from 252 GS subject categories published in 2006, comparing GS, the WoS Core Collection, and Scopus. GS consistently found the largest percentage of citations across all areas (93%–96%), far ahead of Scopus (35%–77%) and WoS (27%–73%). GS found nearly all the WoS (95%) and Scopus (92%) citations. Most citations found only by GS were from non-journal sources (48%–65%), including theses, books, conference papers, and unpublished materials. Many were non-English (19%–38%), and they tended to be much less cited than citing sources that were also in Scopus or WoS. Despite the many unique GS citing sources, Spearman correlations between citation counts in GS and WoS or Scopus are high (0.78-0.99). They are lower in the Humanities, and lower between GS and WoS than between GS and Scopus. The results suggest that in all areas GS citation data is essentially a superset of WoS and Scopus, with substantial extra coverage. 相似文献
2.
《Journal of Informetrics》2014,8(4):912-916
This paper examined the citation impact of Chinese- and English-language articles in Chinese-English bilingual journals indexed by Scopus and Web of Science (WoS). Two findings were obtained from comparative analysis: (1) Chinese-language articles were not biased in citations compared with English-language articles, since they received a large number of citations from Chinese scientists; (2) a Chinese-language community was found in Scopus, in which Chinese-language articles mainly received citations from Chinese-language articles, but it was not found in WoS whose coverage of Chinese-language articles is only one-tenth of Scopus. The findings suggest some implications for academic evaluation of journals including Chinese-language articles in Scopus and WoS. 相似文献
3.
Jiang Li Mark Sanderson Peter Willett Michael Norris Charles Oppenheim 《Journal of Informetrics》2010,4(4):554-563
This paper studies the correlations between peer review and citation indicators when evaluating research quality in library and information science (LIS). Forty-two LIS experts provided judgments on a 5-point scale of the quality of research published by 101 scholars; the median rankings resulting from these judgments were then correlated with h-, g- and H-index values computed using three different sources of citation data: Web of Science (WoS), Scopus and Google Scholar (GS). The two variants of the basic h-index correlated more strongly with peer judgment than did the h-index itself; citation data from Scopus was more strongly correlated with the expert judgments than was data from GS, which in turn was more strongly correlated than data from WoS; correlations from a carefully cleaned version of GS data were little different from those obtained using swiftly gathered GS data; the indices from the citation databases resulted in broadly similar rankings of the LIS academics; GS disadvantaged researchers in bibliometrics compared to the other two citation database while WoS disadvantaged researchers in the more technical aspects of information retrieval; and experts from the UK and other European countries rated UK academics with higher scores than did experts from the USA. 相似文献
4.
Dissertations can be the single most important scholarly outputs of junior researchers. Whilst sets of journal articles are often evaluated with the help of citation counts from the Web of Science or Scopus, these do not index dissertations and so their impact is hard to assess. In response, this article introduces a new multistage method to extract Google Scholar citation counts for large collections of dissertations from repositories indexed by Google. The method was used to extract Google Scholar citation counts for 77,884 American doctoral dissertations from 2013 to 2017 via ProQuest, with a precision of over 95%. Some ProQuest dissertations that were dual indexed with other repositories could not be retrieved with ProQuest-specific searches but could be found with Google Scholar searches of the other repositories. The Google Scholar citation counts were then compared with Mendeley reader counts, a known source of scholarly-like impact data. A fifth of the dissertations had at least one citation recorded in Google Scholar and slightly fewer had at least one Mendeley reader. Based on numerical comparisons, the Mendeley reader counts seem to be more useful for impact assessment purposes for dissertations that are less than two years old, whilst Google Scholar citations are more useful for older dissertations, especially in social sciences, arts and humanities. Google Scholar citation counts may reflect a more scholarly type of impact than that of Mendeley reader counts because dissertations attract a substantial minority of their citations from other dissertations. In summary, the new method now makes it possible for research funders, institutions and others to systematically evaluate the impact of dissertations, although additional Google Scholar queries for other online repositories are needed to ensure comprehensive coverage. 相似文献
5.
Using 17 open-access journals published without interruption between 2000 and 2004 in the field of library and information science, this study compares the pattern of cited/citing hyperlinked references of Web-based scholarly electronic articles under various citation ranges in terms of language, file format, source and top-level domain. While the patterns of cited references were manually examined by counting the live hyperlinked-cited references, the patterns of citing references were examined by using the cited by tag in Google Scholar. The analysis indicates that although language, top-level domain, and file format of citations did not differ significantly for articles under different citation ranges, sources of citation differed significantly for articles in different citation ranges. Articles with fewer citations mostly cite less-scholarly sources such as Web pages, whereas articles with a higher number of citations mostly cite scholarly sources such as journal articles, etc. The findings suggest that 8 out of 17 OA journals in LIS have significant research impact in the scholarly communication process. 相似文献
6.
William H. Walters 《The Reference Librarian》2013,54(1):13-22
This guide describes several information sources that can be used to assist faculty interested in quantitative and qualitative assessments of journal reputation and scholarly impact: Journal Citation Reports, Eigenfactor, Google Scholar Metrics, Elsevier Journal Metrics, Excellence in Research for Australia, Cabell’s International, Web of Science, Scopus, Google Scholar, and Beall’s List. It also introduces the indicators most often used to represent citation impact: impact factor, article influence score, eigenfactor, h5-index, source normalized impact per paper, impact per publication, and SCImago journal rank. Methods of assessing the influence of individual articles are also presented, along with strategies for the identification of predatory or low-quality journals. 相似文献
7.
8.
This article presents the results of a comparative study of Web of Science (WoS), Scopus, and Google Scholar (GS) for a set of 15 business and economics journals. Citations from the three sources were analyzed to determine whether one source is better than another, or whether a new database such as Scopus, or a free database such as GS could replace WoS. The authors concluded that scholars might want to use alternative tools collectively to get a more complete picture of the scholarly impact of an article. 相似文献
9.
Many studies demonstrate differences in the coverage of citing publications in Google Scholar (GS) and Web of Science (WoS). Here, we examine to what extent citation data from the two databases reflect the scholarly impact of women and men differently. Our conjecture is that WoS carries an indirect gender bias in its selection criteria for citation sources that GS avoids due to criteria that are more inclusive. Using a sample of 1250 U.S. researchers in Sociology, Political Science, Economics, Cardiology and Chemistry, we examine gender differences in the average citation coverage of the two databases. We also calculate database-specific h-indices for all authors in the sample. In repeated simulations of hiring scenarios, we use these indices to examine whether women's appointment rates increase if hiring decisions rely on data from GS in lieu of WoS. We find no systematic gender differences in the citation coverage of the two databases. Further, our results indicate marginal to non-existing effects of database selection on women's success-rates in the simulations. In line with the existing literature, we find the citation coverage in WoS to be largest in Cardiology and Chemistry and smallest in Political Science and Sociology. The concordance between author-based h-indices measured by GS and WoS is largest for Chemistry followed by Cardiology, Political Science, Sociology and Economics. 相似文献
10.
《Journal of Informetrics》2007,1(1):26-34
Citation analysis was traditionally based on data from the ISI Citation indexes. Now with the appearance of Scopus, and with the free citation tool Google Scholar methods and measures are need for comparing these tools. In this paper we propose a set of measures for computing the similarity between rankings induced by ordering the retrieved publications in decreasing order of the number of citations as reported by the specific tools. The applicability of these measures is demonstrated and the results show high similarities between the rankings of the ISI Web of Science and Scopus and lower similarities between Google Scholar and the other tools. 相似文献
11.
The paper presents comparative analyses of two publication point systems, The Norwegian and the in-house system from the interdisciplinary Danish Institute of International Studies (DIIS), used as case in the study for publications published 2006, and compares central citation-based indicators with novel publication point indicators (PPIs) that are formalized and exemplified. Two diachronic citation windows are applied: 2006-07 and 2006-08. Web of Science (WoS) as well as Google Scholar (GS) are applied to observe the cite delay and citedness for the different document types published by DIIS, journal articles, book chapters/conference papers and monographs. Journal Crown Indicator (JCI) calculations was based on WoS. Three PPIs are proposed: the Publication Point Ratio (PPR), which measures the sum of obtained publication points over the sum of the ideal points for the same set of documents; the Cumulated Publication Point Indicator (CPPI), which graphically illustrates the cumulated gain of obtained vs. ideal points, both seen as vectors; and the normalized Cumulated Publication Point Index (nCPPI) that represents the cumulated gain of publication success as index values, either graphically or as one overall score for the institution under evaluation.The case study indicates that for smaller interdisciplinary research institutions the cite delay is substantial (2–3 years to obtain a citedness of 50%) when applying WoS for articles. Applying GS implies a shorter delay and much higher citedness for all document types. Statistical significant correlations were only found between WoS and GS and the two publication point systems in between, respectively. The study demonstrates how the nCPPI can be applied to institutions as evaluation tools supplementary to JCI in various combinations, in particular when institutions include humanistic and social science disciplines. 相似文献
12.
This study shows how a journal's influence can be calculated by using citations obtained from Google Scholar and other methods even though the journal is not covered by any citation databases. Influence is measured in terms of foreign contributions, ‘equivalent’ immediacy scores of recent articles, and the calculation of citations and ‘equivalent’ impact factor. A total of 580 articles published in the Medical Journal of Malaysia (MJM) between 2004 and 2008 served as the sample. Very few foreign authors contributed to MJM (12.5%), implying its low regional acceptance as a channel for research communication. Immediacy scores for each year indicate citations were received by recently published articles. A total of 1,164 citations were received by 446 of the 580 articles and the main citing sources were journals (1,083) with reasonable h index and impact factor. Yearly impact scores ranged between 0.367 and 0.616. Higher impact factor scores were obtained by older articles. 相似文献
13.
Many journals post accepted articles online before they are formally published in an issue. Early citation impact evidence for these articles could be helpful for timely research evaluation and to identify potentially important articles that quickly attract many citations. This article investigates whether Microsoft Academic can help with this task. For over 65,000 Scopus in-press articles from 2016 and 2017 across 26 fields, Microsoft Academic found 2–5 times as many citations as Scopus, depending on year and field. From manual checks of 1122 Microsoft Academic citations not found in Scopus, Microsoft Academic’s citation indexing was faster but not much wider than Scopus for journals. It achieved this by associating citations to preprints with their subsequent in-press versions and by extracting citations from in-press articles. In some fields its coverage of scholarly digital libraries, such as arXiv.org, was also an advantage. Thus, Microsoft Academic seems to be a more comprehensive automatic source of citation counts for in-press articles than Scopus. 相似文献
14.
The Web impact of open access social science research 总被引：1，自引：0，他引：1
For a long time, Institute for Scientific Information (ISI) journal citations have been widely used for research performance monitoring of the sciences. For the social sciences, however, the Social Sciences Citation Index® (SSCI®) can sometimes be insufficient. Broader types of publications (e.g., books and non-ISI journals) and informal scholarly indicators may also be needed. This article investigates whether the Web can help to fill this gap. The authors analyzed 1530 citations from Google™ to 492 research articles from 44 open access social science journals. The articles were published in 2001 in the fields of education, psychology, sociology, and economics. About 19% of the Web citations represented formal impact equivalent to journal citations, and 11% were more informal indicators of impact. The average was about 3 formal and 2 informal impact citations per article. Although the proportions of formal and informal online impact were similar in sociology, psychology, and education, economics showed six times more formal impact than informal impact. The results suggest that new types of citation information and informal scholarly indictors could be extracted from the Web for the social sciences. Since these form only a small proportion of the Web citations, however, Web citation counts should first be processed to remove irrelevant citations. This can be a time-consuming process unless automated. 相似文献
15.
[目的/意义] 鉴于Scopus、Web of Science(WoS)与Google Scholar(GS)3个单源数据库在计量学研究和应用中的局限,发展综合利用多源数据信息的复合型引文分析方法可为计量学分析提供一种补充思路。[方法/过程] 以期刊总被引次数这一底层参量为切入点,用图书情报学国际期刊2009-2014年数据为实证基础,尝试对多源数据复合引文算术均值、几何均值及调和均值方法进行比较讨论。[结果/结论] 结果发现,算术均值、几何均值和调和均值虽有差异,但亦有线性关联,应用中可选其一;累计算术均值、几何均值和调和均值与期刊数之间未证实存在布拉德福定律,但在期刊数量等同的三分区内,累计被引均值满足形如n2:n:1的经验分布;多源数据复合引文与单个数据库引文的期刊排名差异呈现"两端小、中间大"之现象;期刊的算术均值排名与GS排名结果更接近,几何均值排名则与Scopus相似度更高,而调和均值与WoS的排名差异最小。 相似文献
16.
以引文数据库Web of Science以及Scopus为文献源,采用文献计量学的方法,针对2004年至今的以Google Scholar为研究主题的文献,从文献量及年代分布、文献类型及语种、作者、期刊、文献被引和主题等方面进行分析,揭示Google Scholar的研究现状。 相似文献
17.
《The Journal of Academic Librarianship》2022,48(1):102484
Although there are at least six dimensions of journal quality, Beall's List identifies predatory Open Access journals based almost entirely on their adherence to procedural norms. The journals identified as predatory by one standard may be regarded as legitimate by other standards. This study examines the scholarly impact of the 58 accounting journals on Beall's List, calculating citations per article and estimating CiteScore percentile using Google Scholar data for more than 13,000 articles published from 2015 through 2018. Most Beall's List accounting journals have only modest citation impact, with an average estimated CiteScore in the 11th percentile among Scopus accounting journals. Some have a substantially greater impact, however. Six journals have estimated CiteScores at or above the 25th percentile, and two have scores at or above the 30th percentile. Moreover, there is considerable variation in citation impact among the articles within each journal, and high-impact articles (cited up to several hundred times) have appeared even in some of the Beall's List accounting journals with low citation rates. Further research is needed to determine how well the citing journals are integrated into the disciplinary citation network—whether the citing journals are themselves reputable or not. 相似文献
18.
Lutz Bornmann Werner Marx Hermann Schier Erhard Rahm Andreas Thor Hans-Dieter Daniel 《Journal of Informetrics》2009,3(1):27-35
Examining a comprehensive set of papers (n = 1837) that were accepted for publication by the journal Angewandte Chemie International Edition (one of the prime chemistry journals in the world) or rejected by the journal but then published elsewhere, this study tested the extent to which the use of the freely available database Google Scholar (GS) can be expected to yield valid citation counts in the field of chemistry. Analyses of citations for the set of papers returned by three fee-based databases – Science Citation Index, Scopus, and Chemical Abstracts – were compared to the analysis of citations found using GS data. Whereas the analyses using citations returned by the three fee-based databases show very similar results, the results of the analysis using GS citation data differed greatly from the findings using citations from the fee-based databases. Our study therefore supports, on the one hand, the convergent validity of citation analyses based on data from the fee-based databases and, on the other hand, the lack of convergent validity of the citation analysis based on the GS data. 相似文献
19.
Mike Thelwall 《Journal of Informetrics》2018,12(2):430-435
Dimensions is a partly free scholarly database launched by Digital Science in January 2018. Dimensions includes journal articles and citation counts, making it a potential new source of impact data. This article explores the value of Dimensions from an impact assessment perspective with an examination of Food Science research 2008–2018 and a random sample of 10,000 Scopus articles from 2012. The results include high correlations between citation counts from Scopus and Dimensions (0.96 by narrow field in 2012) as well as similar average counts. Almost all Scopus articles with DOIs were found in Dimensions (97% in 2012). Thus, the scholarly database component of Dimensions seems to be a plausible alternative to Scopus and the Web of Science for general citation analyses and for citation data in support of some types of research evaluations. 相似文献
20.
In this paper we present a first large-scale analysis of the relationship between Mendeley readership and citation counts with particular documents’ bibliographic characteristics. A data set of 1.3 million publications from different fields published in journals covered by the Web of Science (WoS) has been analyzed. This work reveals that document types that are often excluded from citation analysis due to their lower citation values, like editorial materials, letters, news items, or meeting abstracts, are strongly covered and saved in Mendeley, suggesting that Mendeley readership can reliably inform the analysis of these document types. Findings show that collaborative papers are frequently saved in Mendeley, which is similar to what is observed for citations. The relationship between readership and the length of titles and number of pages, however, is weaker than for the same relationship observed for citations. The analysis of different disciplines also points to different patterns in the relationship between several document characteristics, readership, and citation counts. Overall, results highlight that although disciplinary differences exist, readership counts are related to similar bibliographic characteristics as those related to citation counts, reinforcing the idea that Mendeley readership and citations capture a similar concept of impact, although they cannot be considered as equivalent indicators. 相似文献