Reporting on a mixed methods study carried out in China, this article explores the impact of an educational initiative some years after delivery. Taking data from a three staged longitudinal study, this paper facilitates debate about the nature of Continuing Professional Development (CPD) delivered in a transnational context. To promote such debate a typology of impact is proposed. Using initial evaluation data the researchers designed a comprehensive and detailed evaluation tool to measure the long-term impact of the training. The researchers were interested in identifying whether participation in the learning programmes, designed to encourage social constructivist approach to teaching, had a sustained impact on teachers' and whether these changes transferred into classroom practice. In an attempt to enrich research into transnational interventions such as this, an index of impact was produced and developed to create a typology for the evaluation of educational CPD when offered in an international arena.