The degree of ability differentiation—shared understandings of ability differences—which occurs in classrooms, can be theoretically attributed to the uniformity of criteria comparing students and to the number of dimensions on which those criteria are applied. We identify a cluster of classroom characteristics, labeled “classroom resolution,” hypothesized to produce variation in the degree of ability differentiation: grouping practice, teacher evaluation practice, task differentiation, and student autonomy. Surveying upper-grade students and teachers from seven low resolution and eight high resolution classrooms, we find that consensus on an individual’s academic ranking is higher among classmates, between classmates and self, between teacher and classmates, and between teacher and self in high resolution classrooms. The results suggest that classrooms, varied by resolution, provide different interpretations of ability.