  OpenAlex is a promising open source of scholarly metadata, and competitor to
the established proprietary sources, the Web of Science and Scopus. As OpenAlex
provides its data freely and openly, it permits researchers to perform
bibliometric studies that can be reproduced in the community without licensing
barriers. However, as OpenAlex is a rapidly evolving source and the data
contained within is expanding and also quickly changing, the question naturally
arises as to the trustworthiness of its data. In this empirical paper, we will
study the reference and metadata coverage within each database and compare them
with each other to help address this open question in bibliometrics. In our
large-scale study, we demonstrate that, when restricted to a cleaned dataset of
16,788,282 recent publications shared by all three databases, OpenAlex has
average reference numbers comparable to both Web of Science and Scopus. We also
demonstrate that the comparison of other core metadata covered by OpenAlex
shows mixed results, with OpenAlex capturing more ORCID identifiers, fewer
abstracts and a similar number of Open Access information per article when
compared to both Web of Science and Scopus.
