Availability of digital object identifiers (DOIs) in Web of Science and Scopus

This study aims to shed light on the implementation of the digital object identifier (DOI) in the two most important multidisciplinary databases, namely Web of Science Core Collection and Scopus, within the last decade (2005-2014). The results show a generally increased percentage of items with DOI in all the disciplines in both databases, which provide very similar numbers and trends. While the percentage of citable items with a DOI has already reached 90% in the Sciences and the Social Sciences in 2014, it has remained much lower in the Arts & Humanities, exceeding 50% only since 2013. The observed values for Books and Proceedings are even lower despite the importance of these document types, particularly for the Social Sciences and the Arts & Humanities. The fact that there are still journals with a large number of items still lacking DOIs in 2014 should be alarming for the corresponding editors and should give them reason to enhance the formal quality and visibility of their journals. Finally, scientists are also encouraged to review their publication strategies and to favour publication channels with established DOI assignments. (C) 2015 Elsevier Ltd. All rights reserved.