Astrophysics publications on arXiv, Scopus and Mendeley – A Case Study Judit Bar-Ilan Department of Information Science, Bar-Ilan University, Israel

Astrophysicists Extensive use of the arXiv repository (arxiv.org) 2

141,205 submissions to arXiv in astrophysics between 1991 and ,732 items indexed by WoS during the same period in the astronomy and astrophysics category 3

Scopus Citation database by Elsevier Launched in 2004 with comprehensive citation data from 1994 and onwards Coverage for recent years somewhat bigger than WoS Integrated coverage of proceedings papers More convenient author disambiguation 4

Mendeley Online reference manager, recently acquired by Elsevier Allows users to “bookmark” articles of interest Aggregated information on the number of users who bookmarked a specific articles (readership counts) 5 /

Research setup 100 astrophysicists from the EU and Israel were selected from a sample of 500 researchers who responded to a survey as part of the EU funded ACUMEN project For each of these researchers arXiv submissions, items indexed by Scopus and by Mendeley were retrieved Matching was based primarily on titles Authors and publication sources were also considered 7

Results 8 AverageSTDEV arXiv, no. items Scopus, no. items arXiv-Scopus overlap A recent large scale study on WoS and arXiv found similar results on the overlap (Lariviere et al., 2013)

Results 9 AverageSTDEV sum of citations of Scopus indexed items sum of readers of Scopus indexed items sum of citations of items indexed by Scopus and Mendeley

Results Readership counts are much lower than citation counts on the average Author-level correlations between the two counts are high and significant (r=0.786) 10

Correlations (continued) But, if we consider article-level correlations, these are quite low (0.227), though still significant Comparing with other studies: Article-level correlations are usually higher, around 0.5 In a recent study Mohemmadi and Thelwall (2013) found that for papers in the social sciences and the humanities, median reader counts were higher then median citations 11

Conclusions Comparisons between citations, reader counts and download counts show that usage based and citation based indicators measure different types of influence or impact of scientific publications. Further studies exploring this direction are needed The research reported in this study was funded by the EU FP7 ACUMEN project (Grant agreement: ) 12