{"word_count": 346, "character_count": 2556}
Tsay, M., Tseng, Y. &#38; Wu, T.: Comprehensiveness and uniqueness of commercial databases and open access systems. In: Scientometrics (2019). https://doi.org/10.1007/s11192-019-03252-3 (toll access)"The present study compared the comprehensiveness and uniqueness of coverage betweencommercial databases (Web of Science and Scopus), search engine (Google Scholar),aggregate institutional repositories (OAIster and OpenDOAR), and the open access systemfor physics research (arXiv) on the basis of the journal articles published by Nobel laureates in physics from 2001 to 2013 who were selected as samples in this study. The following conclusions may be drawn from the results of the study:1. Search engine demonstrate greatest coverage comprehensiveness, followed by commercial databases, and lastly by institutional repositories.The comprehensiveness of coverage of publications by selected Nobel laureates in physics can be ranked, from high to low, as: Google Scholar, Scopus, Web of Science, arXiv,OpenDOAR, and OAIster. Google Scholar is the highest, with 96.8% comprehensiveness.Among commercial databases, Scopus has 89.6% comprehensiveness, which is higher thanthat of Web of Science at 84.8%. The coverage comprehensiveness of general institutionalrepositories is lower than that of the subject-specifc arXiv (49%). OpenDOAR is 48.2%,which is higher than OAIster’s 45.3%, the least. Although their comprehensiveness is thelowest among those three types of information resources, institutional repositories haveunique sources the content of which commercial databases may not fully cover.2. The uniqueness of the open access systems is low and shows 0% bibliographic uniqueness compared to Google Scholar.arXiv, OAIster and OpenDOAR all show 0% uniqueness compared to Google Scholar,as Google Scholar could search for bibliographic data from open access systems such asarXiv and other institutional repositories.Comparing the uniqueness of commercial databases (Web of Science and Scopus) withGoogle Scholar, the results are 1.53% and 1.45%, respectively. However, Google Scholarhas greater uniqueness (from 8 to 14%) compared to Web of Science and Scopus. This isbecause Google Scholar covers the index from institutional repositories."Ich kapiers nicht, was mit OpenDOAR gemeint ist. Das ist keine Artikelsuche, sondern ein Verzeichnis der Repositorien! Und wieso man nicht BASE statt OAIster genommen hat, erschließt sich mir ebenfalls nicht. Wer sucht denn noch mit OAIster außer Wissenschaftler, die in China szientometrische Artikel schreiben?