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

TLDR

The rise of the electronic age has produced numerous medical databases on the Web that provide subject‑specific search capabilities and citation analysis tools. This study compared the content coverage and practical utility of PubMed, Scopus, Web of Science, and Google Scholar. The authors extracted information from each database’s official website regarding journal coverage, search features, restrictions, and update frequency, and evaluated keyword search performance and citation analysis using a sample article. All four databases proved usable; PubMed and Google Scholar are free, PubMed offers the most up‑to‑date early articles, Scopus provides about 20 % more coverage than Web of Science but is limited to post‑1995 journals, and Google Scholar delivers broad retrieval yet suffers from inconsistent citation accuracy.

Abstract

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.