OVERVIEW This dataset contains the data from the Knowledge Base (KB) of the PALOMERA project, which collected data and documents relevant to policies regarding open access (OA) books in the European Research Area (ERA). The KB includes policy documents, grey literature, research articles, reports, and outputs of other projects, as well as interview transcripts with stakeholders. The data was collected between 2012 and 2023 through desk research, interviews, and surveys. The KB is openly accessible and can be reused for research and policymaking purposes. The live version of the dataset is available as a browsable dSpace database hosted by OAPEN. https://knowledgebase.oabooks-toolkit.org/ CONTENTS 633 policy documents, grey literature, research articles, reports, and outputs of other projects cover a wide range of OA policies for academic books, including funding mandates, institutional policies, and publisher guidelines (pdf, jpg, txt). Separate “excerpts” files (html, txt) with passages from those documents about OA policies to monographs. 36 anonymised interview transcripts (pdf, txt, jpg) providing insights into the perspectives of different stakeholders on OA policies for academic books. Metadata records in the Dublin Core schema (html), describing each resource. They contain elements like contributor (author, interviewer), date (accessioned, available, issued, snapshot), description (abstract, provenance), identifier (uri, handle), language, publisher, rights, title, type, subject (country, tag, stakeholder) FILES # FILE NAME DESCRIPTION 1. PALOMERA_KB_overview.xlsx Sheet “Content” contains an overview of all the documents in the collection and basic metadata such as their ID, collection, and folder in the dataset, as well as their title, author, country, handle, and brief abstract. Sheet “Definitions” provides definitions of all fields in the table. 2. PALOMERA_KB_overview.xlsx - Content.csv The comma-separated version of the Content sheet described under #1 above. 3. PALOMERA_KB_overview.xlsx - Description.csv The comma-separated version of the Description sheet described under #1 above. 4. PALOMERA_KB_documents.zip. 633 folders, each containing the document (pdf, jpg, txt); excerpts (html, txt); Dublin Core metadata file (xml); DSpace metadata files containing the handle, collection ID, and contents of the record (list of files). 5. PALOMERA_KB_documents.zip 36 folders, each containing an interview transcript document (pdf, jpg, txt); Dublin Core metadata file (xml); DSpace metadata files containing the handle, collection ID, and contents of the record (list of files). METHODOLOGY Full methodology of data collection and sampling is described here: Maryl, M., Manista, G., Păltineanu, S., Stone, G., Laakso, M., Dryer, M., Bandura-Morgan, L., Davidson, A., Silva Ferreira, N. H., Snijder, R., Tummes, J.-P., & Varachkina, H. (2024). PALOMERA D2.1 Report on Compiling the Knowledge Base. Zenodo. https://doi.org/10.5281/zenodo.10777131