The present study offers an alternative methodological approach to the growing body of literature on stance--the linguistic arrangements that construe a writer's perspective on knowledge. A number of recent studies have concluded that control over linguistic stance tends to develop through college and that preferred markers of stance differ by discipline. We know relatively little, however, about how those patterns differ within and between individuals. This study uses a person-centered method, multilevel latent profile analysis, to determine how secondary students in the United States use typical markers of stance in their writing, and to what extent that use varies across texts. The analysis focuses on 338 informal responses produced by 27 rising high school seniors during a college access program. Findings point to wide variation in how students at this level use linguistic markers in their writing, and to the role of the larger instructional context in shaping stance in the informal response genre.