The expansion of Google Scholar versus Web of Science: a longitudinal study

Web of Science (WoS) and Google Scholar (GS) are prominent citation services with distinct indexing mechanisms. Comprehensive knowledge about the growth patterns of these two citation services is lacking. We analyzed the development of citation counts in WoS and GS for two classic articles and 56 articles from diverse research fields, making a distinction between retroactive growth (i.e., the relative difference between citation counts up to mid-2005 measured in mid-2005 and citation counts up to mid-2005 measured in April 2013) and actual growth (i.e., the relative difference between citation counts up to mid-2005 measured in April 2013 and citation counts up to April 2013 measured in April 2013). One of the classic articles was used for a citation-by-citation analysis. Results showed that GS has substantially grown in a retroactive manner (median of 170 % across articles), especially for articles that initially had low citations counts in GS as compared to WoS. Retroactive growth of WoS was small, with a median of 2 % across articles. Actual growth percentages were moderately higher for GS than for WoS (medians of 54 vs. 41 %). The citation-by-citation analysis showed that the percentage of citations being unique in WoS was lower for more recent citations (6.8 % for citations from 1995 and later vs. 41 % for citations from before 1995), whereas the opposite was noted for GS (57 vs. 33 %). It is concluded that, since its inception, GS has shown substantial expansion, and that the majority of recent works indexed in WoS are now also retrievable via GS. A discussion is provided on quantity versus quality of citations, threats for WoS, weaknesses of GS, and implications for literature research and research evaluation.     

A comparison of bibliometric indicators for computer science scholars and journals on Web of Science and Google Scholar

Given the current availability of different bibliometric indicators and of production and citation data sources, the following two questions immediately arise: do the indicators’ scores differ when computed on different data sources? More importantly, do the indicator-based rankings significantly change when computed on different data sources? We provide a case study for computer science scholars and journals evaluated on Web of Science and Google Scholar databases. The study concludes that Google scholar computes significantly higher indicators’ scores than Web of Science. Nevertheless, citation-based rankings of both scholars and journals do not significantly change when compiled on the two data sources, while rankings based on the h index show a moderate degree of variation.     

Coverage of highly-cited documents in Google Scholar,Web of Science,and Scopus: a multidisciplinary comparison

Scientometrics - This study explores the extent to which bibliometric indicators based on counts of highly-cited documents could be affected by the choice of data source. The initial hypothesis is...     

Counting citations in the field of business and management: why use Google Scholar rather than the Web of Science

Research assessment carries important implications both at the individual and institutional levels. This paper examines the research outputs of scholars in business schools and shows how their performance assessment is significantly affected when using data extracted either from the Thomson ISI Web of Science (WoS) or from Google Scholar (GS). The statistical analyses of this paper are based on a large survey data of scholars of Canadian business schools, used jointly with data extracted from the WoS and GS databases. Firstly, the findings of this study reveal that the average performance of B scholars regarding the number of contributions, citations, and the h-index is much higher when performances are assessed using GS rather than WoS. Moreover, the results also show that the scholars who exhibit the highest performances when assessed in reference to articles published in ISI-listed journals also exhibit the highest performances in Google Scholar. Secondly, the absence of association between the strength of ties forged with companies, as well as between the customization of the knowledge transferred to companies and research performances of B scholars such as measured by indicators extracted from WoS and GS, provides some evidence suggesting that mode 1 and 2 knowledge productions might be compatible. Thirdly, the results also indicate that senior B scholars did not differ in a statistically significant manner from their junior colleagues with regard to the proportion of contributions compiled in WoS and GS. However, the results show that assistant professors have a higher proportion of citations in WoS than associate and full professors have. Fourthly, the results of this study suggest that B scholars in accounting tend to publish a smaller proportion of their work in GS than their colleagues in information management, finance and economics. Fifthly, the results of this study show that there is no significant difference between the contributions record of scholars located in English language and French language B schools when their performances are assessed with Google Scholar. However, scholars in English language B schools exhibit higher citation performances and higher h-indices both in WoS and GS. Overall, B scholars might not be confronted by having to choose between two incompatible knowledge production modes, but with the requirement of the evidence-based management approach. As a consequence, the various assessment exercises undertaken by university administrators, government agencies and associations of business schools should complement the data provided in WoS with those provided in GS.     

Universities through the eyes of bibliographic databases: a retroactive growth comparison of Google Scholar,Scopus and Web of Science

Scientometrics - The purpose of this study is to ascertain the suitability of GS’s url-based method as a valid approximation of universities’ academic output measures, taking into...     

Normalizing Google Scholar data for use in research evaluation

Scientometrics - Using bibliometric data for the evaluation of the research of institutions and individuals is becoming increasingly common. Bibliometric evaluations across disciplines require that...     

A simple back-of-the-envelope test for self-citations using Google Scholar author profiles

Scientometrics - The issue of self-citation has received much attention in academia. Widely used and accessible tools such as Google Scholar do not provide information about self-citations....     

Sources of Google Scholar citations outside the Science Citation Index: A comparison between four science disciplines

For practical reasons, bibliographic databases can only contain a subset of the scientific literature. The ISI citation databases are designed to cover the highest impact scientific research journals as well as a few other sources chosen by the Institute for Scientific Information (ISI). Google Scholar also contains citation information, but includes a less quality controlled collection of publications from different types of web documents. We define Google Scholar unique citations as those retrieved by Google Scholar which are not in the ISI database. We took a sample of 882 articles from 39 open access ISI-indexed journals in 2001 from biology, chemistry, physics and computing and classified the type, language, publication year and accessibility of the Google Scholar unique citing sources. The majority of Google Scholar unique citations (70%) were from full-text sources and there were large disciplinary differences between types of citing documents, suggesting that a wide range of non-ISI citing sources, especially from non-journal documents, are accessible by Google Scholar. This might be considered to be an advantage of Google Scholar, since it could be useful for citation tracking in a wider range of open access scholarly documents and to give a broader type of citation impact. An important corollary from our study is that Google Scholar’s wider coverage of Open Access (OA) web documents is likely to give a boost to the impact of OA research and the OA movement.     

Latin American and Caribbean journals indexed in Google Scholar Metrics

Scientometrics - This research analyzes the coverage of Latin American and Caribbean journals in Google Scholar Metrics. It has identified the number of indexed journals by country and compared...     

A longitudinal study of Google Scholar coverage between 2012 and 2013

Harzing (Scientometrics, 2013) showed that between April 2011 and January 2012, Google Scholar has very significantly expanded its coverage in Chemistry and Physics, with a more modest expansion for Medicine and a natural increase in citations only for Economics. However, we do not yet know whether this expansion of coverage was temporary or permanent, nor whether a further expansion of coverage has occurred. It is these questions we set out to respond in this research note. We use a sample of 20 Nobelists in Chemistry, Economics, Medicine and Physics and track their h-index, g-index and total citations in Google Scholar on a monthly basis. Our data suggest that—after a period of significant expansion for Chemistry and Physics—Google Scholar coverage is now increasing at a stable rate. Google Scholar also appears to provide comprehensive coverage for the four disciplines we studied. The increased stability and coverage might make Google Scholar much more suitable for research evaluation and bibliometric research purposes than it has been in the past.     

What I have learned from my Google Scholar and H index

Scientometrics - Following Hartley (Scientometrics 118:375–381, 2019) I attempted to draw lessons from my personal Google citations (>?100,000) by reviewing over 100,000 personal...     

Google Scholar University Ranking Algorithm to Evaluate the Quality of Institutional Research

Education quality has undoubtedly become an important local and international benchmark for education, and an institute’s ranking is assessed based on the quality of education, research projects, theses, and dissertations, which has always been controversial. Hence, this research paper is influenced by the institutes ranking all over the world. The data of institutes are obtained through Google Scholar (GS), as input to investigate the United Kingdom’s Research Excellence Framework (UK-REF) process. For this purpose, the current research used a Bespoke Program to evaluate the institutes’ ranking based on their source. The bespoke program requires changes to improve the results by addressing these methodological issues: Firstly, Redundant profiles, which increased their citation and rank to produce false results. Secondly, the exclusion of theses and dissertation documents to retrieve the actual publications to count for citations. Thirdly, the elimination of falsely owned articles from scholars’ profiles. To accomplish this task, the experimental design referred to collecting data from 120 UK-REF institutes and GS for the present year to enhance its correlation analysis in this new evaluation. The data extracted from GS is processed into structured data, and afterward, it is utilized to generate statistical computations of citations’ analysis that contribute to the ranking based on their citations. The research promoted the predictive approach of correlational research. Furthermore, experimental evaluation reported encouraging results in comparison to the previous modification made by the proposed taxonomy. This paper discussed the limitations of the current evaluation and suggested the potential paths to improve the research impact algorithm.     

Variations in content and format of ISI databases in their different versions: The case of the Science Citation Index in CD-ROM and the Web of Science

The CD-ROM and web versions of the Science Citation Index databases are compared as to their content and format features. Several differences have been detected such as the use of different punctuation marks in both versions and a different organisation of author’s affiliation data. These differences make automatic comparisons of ISI products difficult and they should be considered when matching both databases. Some recommendations to ensure more normalisation and reliability of data are pointed out.     

基于GPS的Google Earth的定位精度分析

众所周知,Google Earth的定位精度远比GPS差,但是Google Earth的影像直观形象,应用广泛,论文的目的旨在将两者的优点相结合,利用GPS的高精度来纠正Google Earth的定位精度。论文首先介绍Google Earth和KML语句格式标准,以及GPS的数据格式,然后提出了改善Google Earth定位精度的方法,并进行了实验。结果表明此方法可以明显提高精度,对于Google Earth的应用大有帮助。     

A novel method for depicting academic disciplines through Google Scholar Citations: The case of Bibliometrics

Scientometrics - This article describes a procedure to generate a snapshot of the structure of a specific scientific community and their outputs based on the information available in Google Scholar...