Although agricultural innovation systems (AIS) have recently received considerable attention in academic and development circles, links between an AIS's regional specifications and structural-functional analysis have been neglected. This paper aims to understand how regional and structural dimensions determine systemic problems and blocking mechanisms that, in turn, hinder a regional AIS's function.

Competing models of innovation informing agricultural extension, such as transfer of technology, participatory extension and technology development, and innovation systems have been proposed over the last decades. These approaches are often presented as antagonistic or even mutually exclusive. This article shows how practitioners in a rural innovation system draw on different aspects of all three models, while creating a distinct local practice and discourse. We revisit and deepen the critique of Vietnam’s “model” approach to upland rural development, voiced a decade ago in this journal.