Cultures of performative accountability in education have been on the rise globally since the 1980s. Accordingly, teachers have increasingly been encouraged to understand their work in relation to particular forms of 'evidence'. All evidence, however, is not regarded as equal, and sources of evidence privileged within cultures of performative accountability are typically narrowly rendered, apparently 'objective', externally generated and largely quantified in form. Recent research from the United States, Australia and England has suggested that such cultures may be re-shaping teacher practice and identity. Performative accountability, however, is not the only form of accountability, and this paper explores the tensions between performative and 'intelligent' accountability in teachers' work and lives, reporting on research investigating Australian teachers' understanding of and engagement with data and research as well as evidence of their work more broadly. The paper contributes to the literature on the datafication of teaching and debates regarding the nature and role of evidence in teaching work. Ultimately, we argue that spaces for rich understandings of evidence, present but not dominant in contemporary education policy, must be protected and extended in order for the current focus on evidence to generatively -- and intelligently -- reflect and shape teachers' work.