The assessment of literacy continues to be the focus of debate. Attention has been given to textual features of students' writing, such as vocabulary, grammar and generic structures. We demonstrate how students' success in school is also dependent on their enactment of the category 'child'. We examine the micro-sociological issue of how students and a teacher interpret and deploy practices appropriate to their status as 'child-student' and 'adult-teacher'. Drawing on work that examines the day-to-day, moment-by-moment enactment of institutional and folk theories of the 'child', we interrogate classroom talk and students' writing for the versions of the 'child' constructed there, the manner in which suppositions about the nature of childhood are enacted, and the implications of normative presumptions about the nature of the 'child' for students' assessment. �� 2001 Taylor & Francis Ltd.