Comparing test searches in PubMed and Google Scholar.

Google Scholar has been met with both enthusiasm and criticism since its introduction in 2004. This search engine provides a simple way to access “peer-reviewed papers, theses, books, abstracts, and articles from academic publishers' sites, professional societies, preprint repositories, universities and other scholarly organizations” [1]. An obvious strength of Google Scholar is its intuitive interface, as the main search engine interface consists of a simple query box. In contrast, databases, such as PubMed, utilize search interfaces that offer a greater variety of advanced features. These additional features, while powerful, often lead to a complexity that may require a substantial investment of time to master. It has been observed that Google Scholar may allow searchers to “find some resources they can use rather than be frustrated by a database's search screen” [2]. Some even feel that “Google Scholar's simplicity may eventually consume PubMed” [3]. Along with ease of use, Google Scholar carries the familiar “Google” brand name. As Kennedy and Price so aptly stated, “College students AND professors might not know that library databases exist, but they sure know Google” [4]. The familiarity of Google may allow librarians and educators to ease students into the scholarly searching process by starting with Google Scholar and eventually moving to more complex systems. Felter noted that “as researchers work with Google Scholar and reach limitations of searching capabilities and options, they may become more receptive to other products” [5]. Google Scholar is also thought to provide increased access to gray literature [2], as it retrieves more than journal articles and includes preprint archives, conference proceedings, and institutional repositories [6]. Google Scholar also includes links to the online collections of some academic libraries. Including these access points in Google Scholar retrieval sets may ultimately help more users reach more of their own institution's subscriptions [7]. While its advantages are substantial, Google Scholar is not without flaws. The shortcomings of the system and its search interface have been well documented in the literature and include lack of reliable advanced search functions, lack of controlled vocabulary, and issues regarding scope of coverage and currency. Table 1 summarizes some of the reported criticisms of Google Scholar. Table 1 Criticisms of Google Scholar Vine found that while Google Scholar pulls in data from PubMed, many PubMed records are missing [20], and that Google Scholar also lacks features available in MEDLINE [12]. Others have noted that Google Scholar should not be the first or sole choice when searching for patient care information, clinical trials, or literature reviews [23,24]. Thorough review and testing of Google Scholar, being an approach similar to that used to evaluate licensed resources, is necessary to better understand its strengths and limitations. As Jacso states, “professional searchers must do sample test searches and correctly interpret the results to corroborate claims and get factual information about databases” [18]. This paper compares and contrasts a variety of test searches in PubMed and Google Scholar to gain a better understanding of Google Scholar's searching capabilities.