Drawing on seven years of research in Dutch-medium schools in Belgium, Jaspers investigates how teachers at monolingual schools deal with the fact that they teach linguistically diverse groups of pupils. He demonstrates that this results in variable, ambivalent, and often contradictory practices and opinions, as teachers continuously juggle competing social and linguistic values with what works in a given classroom. Recognizing that inconsistency and contradiction in teacher behavior is a result of adjusting to variable circumstances means understanding that a single approach may not work, and that a convincing and critical sociolinguistics can generate potential change when it insists on a variety of opinions about language and on the prospect of informed deliberation and debate. Jaspers argues that this capacity is crucial for attending to the multiple, competing goals that classroom interaction presents; that it typically invites inconsistent, albeit rational, behavior; and that if this inconsistency is common and chronic, researchers on language-in-education need to improve their radar and develop a different kind of dialogue with teachers.