CiteULike: JSicot's gscholar

Comparison of PubMed, Scopus, Web of Science, and Google Scholar: strengths and weaknesses.

Matthew E Falagas — 2007-09-24T06:31:23-00:00

FASEB J (20 September 2007)

The evolution of the electronic age has led to the development of numerous medical databases on the World Wide Web, offering search facilities on a particular subject and the ability to perform citation analysis. We compared the content coverage and practical utility of PubMed, Scopus, Web of Science, and Google Scholar. The official Web pages of the databases were used to extract information on the range of journals covered, search facilities and restrictions, and update frequency. We used the example of a keyword search to evaluate the usefulness of these databases in biomedical information retrieval and a specific published article to evaluate their utility in performing citation analysis. All databases were practical in use and offered numerous search facilities. PubMed and Google Scholar are accessed for free. The keyword search with PubMed offers optimal update frequency and includes online early articles; other databases can rate articles by number of citations, as an index of importance. For citation analysis, Scopus offers about 20% more coverage than Web of Science, whereas Google Scholar offers results of inconsistent accuracy. PubMed remains an optimal tool in biomedical electronic research. Scopus covers a wider journal range, of help both in keyword searching and citation analysis, but it is currently limited to recent articles (published after 1995) compared with Web of Science. Google Scholar, as for the Web in general, can help in the retrieval of even the most obscure information but its use is marred by inadequate, less often updated, citation information.-Falagas, M. E., Pitsouni, E I., Malietzis, G. A., and Pappas, G. Comparison of Pub Med, Scopus, Web of Science, and Google Scholar: strengths and weaknesses.

Google Scholar : the new generation of citation indexes

Alireza Noruzi — 2007-12-12T20:58:46-00:00

LIBRI, Vol. 55, No. 4. (2005)

Google Scholar (http://scholar.google.com/) provides a new method of locating potentially relevant articles on a given subject by identifying subsequent articles that cite a previously published article. An important feature of Google Scholar is that researchers can use it to trace interconnections among authors citing articles on the same topic and to determine the frequency with which a specific article is cited by others as it has a "cited by" feature. We will begin with an overview of how to use it for citation analysis, and then progress through advanced search techniques. This study also compares the citation counts provided by Web of Science and Google Scholar for articles in the field of Webometrics. We make several suggestions for improvement it. Finally, it concludes that Google Scholar provides a free alternative or complement to other citation indexes.

Metalib and Google Scholar: a user study

Glenn Haya — 2007-11-24T07:30:59-00:00

Online Information Review, Vol. 31, No. 3. (2007), pp. 365-375.

Purpose – This paper aims to understand how students experience the search tools Google Scholar and Metalib and the role of prior instruction. Design/methodology/approach – A total of 32 undergraduate students searched academic articles for their thesis work. Searches were recorded using Morae software and were analysed along with the number of articles saved and responses to a questionnaire. All searched with both tools. Half of the students received training before searching. Findings – Google Scholar performed better in almost all measures. Training had a positive effect on the amount and quality of articles saved. Responses to Google Scholar were more positive than to Metalib. However, the students were not overwhelmingly enthusiastic about either of the tools. Research limitations/implications – Each Metalib implementation is to some extent unique, which limits the extent to which results can be generalised to other implementations. Practical implications – Training is valuable for both tools. The user interface to Metalib does not conform with students' expectations and needs further improvement. Both tools strive to be a first alternative search tool for academic literature but neither performed well enough in this study to recommend it to be used in that role in an academic library setting. Originality/value – These tools are important to academic libraries but few user studies have been published, particularly on Google Scholar. To one's knowledge no other user study on these tools has looked at the effects of instruction. Keywords: Customer satisfaction, Research methods, Search engines, Students, User interfaces

An exploratory study of Google Scholar

Philipp Mayr — 2007-11-23T14:45:40-00:00

Online Information Review, Vol. 31, No. 6. (2007), pp. 814-830.

Purpose – The purpose of this paper is to discuss the new scientific search service Google Scholar (GS). It aims to discuss this search engine, which is intended exclusively for searching scholarly documents, and then empirically test its most important functionality. The focus is on an exploratory study which investigates the coverage of scientific serials in GS. Design/methodology/approach – The study is based on queries against different journal lists: international scientific journals from Thomson Scientific (SCI, SSCI, AH), open access journals from the DOAJ list and journals from the German social sciences literature database SOLIS as well as the analysis of result data from GS. All data gathering took place in August 2006. Findings – The study shows deficiencies in the coverage and up-to-dateness of the GS index. Furthermore, the study points out which web servers are the most important data providers for this search service and which information sources are highly represented. The paper can show that there is a relatively large gap in Google Scholar's coverage of German literature as well as weaknesses in the accessibility of Open Access content. Major commercial academic publishers are currently the main data providers. Research limitations/implications – Five different journal lists were analysed, including approximately 9,500 single titles. The lists are from different fields and of various sizes. This limits comparability. There were also some problems matching the journal titles of the original lists to the journal title data provided by Google Scholar. The study was only able to analyse the top 100 Google Scholar hits per journal. Practical implications – The paper concludes that Google Scholar has some interesting pros (such as citation analysis and free materials) but the service cannot be seen as a substitute for the use of special abstracting and indexing databases and library catalogues due to various weaknesses (such as transparency, coverage and up-to-dateness). Originality/value – The authors do not know of any other study using such a brute force approach and such a large empirical basis. The study can be considered as using brute force in the sense that it gathered lots of data from Google and then analysed the data in a macroscopic way.

Use Google Scholar, Scopus and Web of Science for Comprehensive Citation Tracking

Lorie Kloda — 2007-09-23T19:00:11-00:00

Evidence Based Library and Information Practice, Vol. 3, No. 2. (2007), pp. 87-90.

Objective – To determine whether three competing citation tracking services result in differing citation counts for a known set of articles, and to assess the extent of any differences. Design – Citation analysis, observational study. Setting – Three citation tracking databases: Google Scholar, Scopus and Web of Science. Subjects – Citations from eleven journals each from the disciplines of oncology and condensed matter physics for the years 1993 and 2003. Methods – The researchers selected eleven journals each from the list of journals from Journal Citation Reports 2004 for the categories “Oncology” and “Condensed Matter Physics” using a systematic sampling technique to ensure journals with varying impact factors were included. All references from these 22 journals were retrieved for the years 1993 and 2003 by searching three databases: Web of Science, INSPEC, and PubMed. Only research articles were included for the purpose of the study. From these, a stratified random sample was created to proportionally represent the content of each journal (oncology 1993: 234 references, 2003: 259 references; condensed matter physics 1993: 358 references, 2003: 364 references). In November of 2005, citations counts were obtained for all articles from Web of Science, Scopus and Google Scholar. Due to the small sample size and skewed distribution of data, non-parametric tests were conducted to determine whether significant differences existed between sets. Main results – For 1993, mean citation counts were highest in Web of Science for both oncology (mean = 45.3, SD = 77.4) and condensed matter physics (mean = 22.5, SD = 32.5). For 2003, mean citation counts were higher in Scopus for oncology (mean = 8.9, SD = 12.0), and in Web of Science for condensed matter physics (mean = 3.0, SD = 4.0). There was not enough data for the set of citations from Scopus for condensed matter physics for 1993 and it was therefore excluded from analysis. A Friedman test to measure for differences between all remaining groups suggested a significant difference existed, and so pairwise post-hoc comparisons were performed. The Wilcoxon Signed Ranked tests demonstrated significant differences “in citation counts between all pairs (p < 0.001) except between Google Scholar and Scopus for CM physics 2003 (p = 0.119).” The study also looked at the number of unique references from each database, as well as the proportion of overlap for the 2003 citations. In the area of oncology, there was found to be 31% overlap between databases, with Google Scholar including the most unique references (13%), followed by Scopus (12%) and Web of Science (7%). For condensed matter physics, the overlap was lower at 21% and the largest number of unique references was found in Web of Science (21%), with Google Scholar next largest (17%) and Scopus the least (9%). Citing references from Google Scholar were found to originate from not only journals, but online archives, academic repositories, government and non-government white papers and reports, commercial organizations, as well as other sources. Conclusion – The study does not confirm the authors’ hypothesis that differing scholarly coverage would result in different citation counts from the three databases. While there were significant differences in mean citation rates between all pairs of databases except for Google Scholar and Scopus in condensed matter physics for 2003, no one database performed better overall. Different databases performed better for different subjects, as well as for different years, especially Scopus, which only includes references starting in 1996. The results of this study suggest that the best citation database will depend on the years being searched as well as the subject area. For a complete picture of citation behaviour, the authors suggest all three be used.

An exploratory study of Google Scholar

Philipp Mayr — 2007-08-27T11:28:03-00:00

(2007)

Purpose – This paper discusses the new scientific search service Google Scholar (GS). This search engine, intended for searching exclusively scholarly documents, will be described with its most important functionality and then empirically tested. The focus is on an exploratory study which investigates the coverage of scientific serials in GS. Design/methodology/approach – The study is based on queries against different journal lists: international scientific journals from Thomson Scientific (SCI, SSCI, AH), Open Access journals from the DOAJ list and journals of the German social sciences literature database SOLIS as well as the analysis of result data from GS. All data gathering took place in August 2006. Findings – The study shows deficiencies in the coverage and up-to-dateness of the GS index. Furthermore, the study points up which web servers are the most important data providers for this search service and which information sources are highly represented. We can show that there is a relatively large gap in Google Scholar’s coverage of German literature as well as weaknesses in the accessibility of Open Access content. Major commercial academic publishers are currently the main data providers. Research limitations/implications – Five different journal lists were analyzed, including approximately 9,500 single titles. The lists are from different fields and of various sizes. This limits comparability. There were also some problems matching the journal titles of the original lists to the journal title data provided by Google Scholar. We were only able to analyze the top 100 Google Scholar hits per journal. Practical implications – We conclude that Google Scholar has some interesting pros (such as citation analysis and free materials) but the service can not be seen as a substitute for the use of special abstracting and indexing databases and library catalogues due to various weaknesses (such as transparency, coverage and up-to-dateness). Originality/value – We do not know of any other study using such a brute force approach and such a large empirical basis. Our study can be considered as using brute force in the sense that we gathered lots of data from Google, then analyzed the data in a macroscopic way.

Google Scholar and 100% Availability of Information.

Jeffrey Pomerantz — 2007-06-24T13:46:29-00:00

Information Technology and Libraries, Vol. 1, No. 25. (2006), pp. 52-56.

Google Scholar : the new generation of citation indexes

A Noruzi — 2006-02-13T08:11:30-00:00

LIBRI, Vol. 55, No. 4., pp. 170-180.

Google Scholar (http://scholar.google.com) provides a new method of locating potentially relevant articles on a given subject by identifying subsequent articles that cite a previously published article. An important feature of Google Scholar is that researchers can use it to trace interconnections among authors citing articles on the same topic and to determine the frequency with which others cite a specific article, as it has a "cited by" feature. This study begins with an overview of how to use Google Scholar for citation analysis and identifies advanced search techniques not well documented by Google Scholar. This study also compares the citation counts provided by Web of Science and Google Scholar for articles in the field of "Webometrics." It makes several suggestions for improving Google Scholar. Finally, it concludes that Google Scholar provides a free alternative or complement to other citation indexes.

Google Scholar Citations and Google Web/URL Citations: A Multi-Discipline Exploratory Analysis

K Kousha — 2006-06-14T07:54:33-00:00

(2006)

In this paper we introduce a new data gathering method “Web/URL Citation” and use it and Google Scholar as a basis to compare traditional and Web-based citation patterns across multiple disciplines. For this, we built a sample of 1,650 articles from 108 Open Access (OA) journals published in 2001 in four science and four social science disciplines. We recorded the number of citations to the sample articles using several methods based upon the ISI Web of Science, Google Scholar and the Google search engine (Web/URL citations). For each discipline, we found significant correlations between ISI citations and both Google Scholar and Google Web/URL citations; with similar results when using total or average citations, and when comparing within and across (most) journals. We also investigated disciplinary differences. Google Scholar citations were more numerous than ISI citations in our four social science disciplines as well as in computer science, suggesting that Google Scholar is a more comprehensive tool for citation tracking in the social sciences and perhaps also in fast-moving fields where conference papers are highly valued and published online. The results for Web/URL citations suggested that counting a maximum of one hit per site produces a better measure for assessing the impact of OA journals or articles, because replicated web citations are very common within individual sites. The results can be considered as additional evidence that there is some commonality between traditional and Web-extracted citations.

Google Scholar Versus Metasearch Systems

T Sadeh — 2007-05-12T15:10:46-00:00

High Energy Physics Libraries Webzine, No. 12. (March 2006)

At the end of 2004, Google launched the beta version of a new service, Google Scholar, which provides a single repository of scholarly information for researchers. Will this service replace metasearch systems? Metasearch systems are based on just-in-time processing, whereas Google Scholar, like other federated searching systems, is based on just-in-case processing. This underlying technology, along with Google Scholar's exceptional capabilities, accords Google Scholar a unique position among other scholarly resources. However, a year after its beta release, Google Scholar is still facing a number of challenges that cause librarians to question its value for scholarly research. Nevertheless, it has become popular among researchers, and the library community is looking for ways to provide patrons with guidelines for the most beneficial manner of using this new resource. Metasearch systems have several advantages over Google Scholar. We anticipate that in the foreseeable future, libraries will continue to provide access to their electronic collections via their branded, controlled metasearch system.

Impact of Data Sources on Citation Counts and Rankings of LIS Faculty: Web of Science vs. Scopus and Google Scholar

Lokman Meho — 2007-06-08T15:06:31-00:00

(2007)

A New Era in Citation and Bibliometric Analyses: Web of Science, Scopus, and Google Scholar

Lokman Meho — 2007-06-08T13:09:22-00:00

(2006)

Three options for citation tracking: Google Scholar, Scopus and Web of Science

Nisa Bakkalbasi — 2007-06-08T13:02:49-00:00

Biomedical Digital Libraries, Vol. 3, No. 1. (2006)

Researchers turn to citation tracking to find the most influential articles for a particular topic and to see how often their own published papers are cited. For years researchers looking for this type of information had only one resource to consult: the Web of Science from Thomson Scientific. In 2004 two competitors emerged ? Scopus from Elsevier and Google Scholar from Google. The research reported here uses citation analysis in an observational study examining these three databases; comparing citation counts for articles from two disciplines (oncology and condensed matter physics) and two years (1993 and 2003) to test the hypothesis that the different scholarly publication coverage provided by the three search tools will lead to different citation counts from each.