The presentation will zoom in on the chosen aspects of curating a set of 300.000 records of bibliographic metadata on book-form translations into Polish sourced from the National Library of Poland in the framework of the project: The Hidden Collection: Online database of Polish translated literature since 1918. It will demonstrate the value of combining algorithmic methods of data processing with human-led qualitative verification and amelioration of bibliographic metadata for completeness, accuracy and structure, so that they best reflect translation as a complex cultural and social phenomenon. This will be done on the basis of data on the editions made to our set by more than 60 experts: translators, librarians and researchers of translation, languages and cultures who verified the data in terms of completeness and accuracy and ameliorated them on the basis of their expertise, qualitative research and orientation in existing literature. The presentation will engage with the question of whether, and when, qualitatively ameliorating bibliographic data can, indeed, lead to more reliable results – at different levels of detail and granularity, as well as in consideration of the possible biases in representation of translators and translations in bibliographic metadata.