An exploratory study of Google Scholar

Purpose - The purpose of this paper is to discuss the new scientific search service Google Scholar 1 May 2007 (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, AI-I), 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.