Why educational change accumulates rather than replaces in Ukrainian natural science education from 1950 to 2022

Abstract Educational change theory commonly assumes that reforms replace what came before: outdated curricula give way to modern ones, teacher-centered pedagogy yields to student-centered approaches, and ideological content is displaced by scientific objectivity. We argue that this replacement assumption describes the trajectory of post-Soviet educational reform poorly. Drawing on a documentary corpus of 393 catalogued items spanning seven decades of Ukrainian natural science education (1950–2022), of which 101 are primary legislative, archival and curricular documents, we show that successive reforms—Soviet polytechnicalization, post-independence nationalization, and European competency-based frameworks—did not displace their predecessors. Formal structures established under one settlement persisted alongside those introduced by the next, producing a palimpsest in which older arrangements remain legible beneath newer policy language. We propose that such layering contributes to the persistent “implementation gap” that reform literature treats as a problem to be solved, and that friction between layers is one of its sources—alongside, rather than instead of, resource constraint, assessment incentives and implementation capacity. The disruption following Russia’s 2022 invasion is examined as a critical case rather than as an experiment: it indicates which arrangements the system treated as indispensable under acute stress, while confounding institutional depth with the resource intensity of the practices concerned. A brief comparison with Estonia and Belarus is offered as a source of hypotheses for comparative research rather than as an established contrast. We suggest that a palimpsest model, grounded in Tyack and Cuban’s grammar of schooling and extended through institutional analysis, offers a more productive framework for understanding educational transformation than linear models, with implications for how the assumptions embedded in SDG 4 and the global reform agenda are understood.