  One of the features of modern science is the formation of stable large
collaborations of researchers working together within the projects that require
the concentration of huge financial and human resources. Results of such common
work are published in scientific papers by large co-authorship teams that
include sometimes thousands of names. The goal of this work is to study the
influence of such publications on the values of scientometric indicators
calculated for individuals, research groups and science of Ukraine in general.
Bibliometric data related to Ukraine, some academic institutions and selected
individual researchers were collected from Scopus database and used for our
study. It is demonstrated that while the relative share of publications by
collective authors is comparatively small, their presence in a general pool can
lead to statistically significant effects. The obtained results clearly show
that traditional quantitative approaches for research assessment should be
changed in order to take into account this phenomenon. Keywords: collective
authorship, scientometrics, group science, Ukraine.
