From indexation policies through citation networks to normalized citation impacts: Web of Science, Scopus, and Dimensions as varying resonance chambers

Authors : Stephan Stahlschmidt, Dimity Stephen

Dimensions was introduced as an alternative bibliometric database to the well-established Web of Science (WoS) and Scopus, however all three databases have fundamental differences in coverage and content, resultant from their owners’ indexation philosophies.

In light of these differences, we explore here, using a citation network analysis and assessment of normalised citation impact of “duplicate” publications, whether the three databases offer structurally different perspectives of the bibliometric landscape or if they are essentially homogenous substitutes.

Our citation network analysis of core and exclusive 2016-2018 publications revealed a large set of core publications indexed in all three databases that are highly self-referential. In comparison, each database selected a set of exclusive publications that appeared to hold similarly low levels of relevance to the core set and to one another, with slightly more internal communication between exclusive publications in Scopus and Dimensions than WoS.

Our comparison of normalised citations for 41,848 publications indexed in all three databases found that German sectors were valuated as more impactful in Scopus and Dimensions compared to WoS, particularly for sectors with an applied research focus.

We conclude that the databases do present structurally different perspectives, although Scopus and Dimensions with their additional circle of applied research vary more from the more base research-focused WoS than they do from one another.

URL : https://arxiv.org/abs/2106.01695

Merits and Limits: Applying open data to monitor open access publications in bibliometric databases

Authors : Aliakbar Akbaritabar, Stephan Stahlschmidt

Identifying and monitoring Open Access (OA) publications might seem a trivial task while practical efforts prove otherwise. Contradictory information arise often depending on metadata employed.

We strive to assign OA status to publications in Web of Science (WOS) and Scopus while complementing it with different sources of OA information to resolve contradicting cases.

We linked publications from WOS and Scopus via DOIs and ISSNs to Unpaywall, Crossref, DOAJ and ROAD. Only about 50% of articles and reviews from WOS and Scopus could be matched via a DOI to Unpaywall.

Matching with Crossref brought 56 distinct licences, which define in many cases the legally binding access status of publications. But only 44% of publications hold only a single licence on Crossref, while more than 50% have no licence information submitted to Crossref.

Contrasting OA information from Crossref licences with Unpaywall we found contradictory cases overall amounting to more than 25%, which might be partially explained by (ex-)including green OA.

A further manual check found about 17% of OA publications that are not accessible and 15% non-OA publications that are accessible through publishers’ websites. These preliminary results suggest that identification of OA state of publications denotes a difficult and currently unfulfilled task.

URL : https://arxiv.org/abs/1902.03937