This article reports on an Economic and Social Research Council-funded study into secondary-aged writers' compositional processes, both as observed in a naturalistic classroom setting and as gathered through post hoc reflections. The sample comprised 38 children drawn from Year 9 and Year 11 who were observed, using an annotated timeline, responding to a writing task in the classroom and were subsequently interviewed, using stimulated recall. The initial analysis of the pause and writing patterns observed during the writing task revealed different writing profiles for different writers, and subsequent analysis suggests tentatively that writers of different proficiency may present differing writing profiles. These patterns of composition are then illustrated further through use of the interview data, indicating the writers' awareness of their own composing processes. Finally, the article considers the pedagogic and theoretical implications of these findings, in particular the need for further confirmatory research. (Contains 6 tables and 6 figures.)