Exemplars are samples which illustrate dimensions of quality and enable students to understand assessment expectations. The theoretical basis for using exemplars lies principally in social constructivist approaches to assessment and the notion of tacit knowledge. Through a constructivist grounded theory methodology, this paper theorises how twelve teachers of English for Academic Purposes managed the process of using exemplars. Data collection involved triangulation between semi-structured interviews and classroom observations of the twelve teachers. Data analysis utilised constructivist grounded theory strategies: initial and focused coding, memoing and abductive reasoning. The findings analyse teacher decision-making in relation to exemplar use; the different ways in which criteria are deployed in conjunction with exemplars; and controlled or more open dialogues about exemplars. The theoretical contribution arises principally from a threefold typology comprising structured, guided discovery and dialogic approaches to managing the use of exemplars. It is suggested that a mediated dialogic approach has most potential to maximise learning benefits of exemplar use. Implications for practice explore tensions between what is recommended in the exemplars literature and the complexities of classroom implementation. Methodological implications arise from the triangulation between observations and interviews, and the discursive gap between social constructivist approaches and theories of mediation.