Google Scholar vs. Dblp vs. Microsoft Academic Search: An Indexing Comparison for Software Engineering Literature

Background: One of the necessary conditions for any substantial research work is to synthesis the depth and the breath of the existing published literature on that topic. It is, thus, of extreme importance for a researcher to understand and look for both credible and exhaustive information sources. This first (important) step can be made significantly easier if the researcher can employ a more systematic way to extract the maximum of the literature on the topic. Objective: Essentially, the objective of this preliminary study is to rank three freely available academic search engines (Google Scholar, DBLP, Microsoft Academic Search) on the basis of the indexed Software Engineering academic literature they contain. Method: We have used a systematic mapping to conduct the study. Results: After extracting and analyzing 1067 secondary studies (from 18 tertiary studies), we have concluded that Google Scholar has indexed 98.96%, DBLP has indexed 93.43%, and Microsoft Academic Search engine has indexed 97.46% of the secondary studies. Thus, this implies that Google Scholar and Microsoft Academic Search might be a better-suited option for searching for secondary studies.