This specification (v0.3) contains 15 metrics proposed by FAIRsFAIR to evaluate the FAIRness of research data objects in Trustworthy Digital Repositories (TDRs). We improved the metrics based on a focus group's feedback and the RDA-endorsed FAIR data maturity model guidelines and specification. A total of 33 FAIR stakeholders, such as research communities, data service providers, standard bodies, and coordination fora participated in the focus group. In its current form, the specification applies metrics that may correspond to all or part of one or more FAIR principles. We will refine and revise the metrics through several iterations based on feedback from stakeholders interested in FAIR, and on implementation of our use cases to demonstrate FAIR assessment. The assessment focuses on generally applicable data/metadata characteristics until domain/community-driven criteria have been agreed (e.g., appropriate schemas and required elements for usage/access control). FAIR enabling services and repositories are vital to ensure that research data objects remain FAIR over time. Machine-readable services (e.g., registries) and documents (e.g., policies) are required to enable proposed automated tests. Corrigendum Footnote 6 This should read: Research Data Journal - FAIR Data Review, https://docs.google.com/forms/d/e/1FAIpQLSd8_pd2r2SnjCVfCC3CHhEUHZzv2MTRC3RTh0S2YTvbVJj87Q/viewform Footnote 7 This should read: https://docs.google.com/forms/d/e/1FAIpQLSf7t1Z9IOBoj5GgWqik8KnhtH3B819Ch6lD5KuAz7yn0I0Opw/viewformm

We are seeking wide feedback on the object metrics which will inform discussions and further work within FAIRsFAIR as well as collaborations with other relevant projects. Comments and suggestions can be added until 09.10.2020 here.