Open Here, There, and Everywhere? A Comparative Review of Divergences in Open Access Typologies and Definitions in Monitoring Instruments - Archive ouverte HAL

Louis Bachaud, Didier Torny. Open Here, There, and Everywhere? A Comparative Review of Divergences in Open Access Typologies and Definitions in Monitoring Instruments. 2026. ⟨hal-05661835⟩

Open Access (OA) monitoring has become a policy instrument for governments, institutions, and research funders globally, yet the typologies and definitions underlying OA monitors have never been systematically compared. Drawing on a global dataset of 30 OA monitors, we conduct the first systematic comparative review of their operational OA definitions and typologies. Our findings reveal dynamics of standardization, as well as enduring differences. Unpaywall/OpenAlex occupies a near-hegemonic position as metadata provider (77% of monitors), shaping classification choices across the landscape. Nevertheless, significant heterogeneity persists: monitors diverge on whether Bronze publications constitute true OA, on how to count Green OA publications, on the relevance of open licenses, and on whether economic dimensions (APCs, Diamond OA) belong in typologies at all. Only two monitors share both a common typology and identical operational criteria. These divergences pose challenges for cross-national comparability and call for greater methodological transparency in open science monitoring infrastructures.