Comparing bibliometric country-by-country rankings derived from the Web of Science and Scopus: the effect of poorly cited journals in oncology

This article addresses the robustness of country-by-country rankings according to the number of published articles and their average citation impact in the field oncology. It compares rankings based on bibliometric indicators derived from the Web of Science (WoS) with those calculated from Scopus. It is found that the oncological journals in Scopus not covered by WoS tend to be nationally oriented journals, i.e. they mainly serve a national research community, and play as of yet a more peripheral role in the international journal communication system. In expanding the set of WoS journals with Scopus journals not indexed for WoS, the countries that profit most in terms of percentage of published documents tend to show a decline in their average citation rate. This paradoxical finding is further explained by mathematical—statistical considerations, and interpreted as a short term effect. The paper discusses its implications for the construction of bibliometric indicators.