Comparing bibliographic descriptions in seven free-access databases

This communication aims to analyse the information that a large set of free-access databases (i.e., Crossref, Dimensions, Microsoft Academic, OpenAlex, Scilit, Semantic Scholar, The Lens) provides about indexed publications in their databases. Using a random sample of 116k publications from Crossref, each database was queried to retrieve the same document list with the purpose of comparing the metadata of their publications. The results show that the completeness degree is different between databases and that the search engines show more problems to extract abstracts and assign document typologies. Dimensions is the product that obtain the highest completeness percentages in abstracts, open access documents, bibliographic data and document types.