The study reported in this article examines how teachers read and respond to their students' Stanford Achievement Test 10 (SAT 10) scores with the goal of investigating the assumption that data-based teaching practice is more "objective" and less susceptible to divergent teacher interpretation. The study uses reader response theory to frame teachers' responses to their students' SAT 10 test scores as interpretations of a text shaped through unexamined assumptions and political interests related to accountability, rather than strictly statistical "official" interpretations of "objective" data. The findings illustrate that teachers' interpretations of SAT 10 data that inform their data-based practice are vulnerable to the pervasive influence of local school responses to accountability pressures. More specifically, the findings reveal how moral and discursive texts imbricated in accountability discourses mediate the ways in which teachers read and respond to their students' SAT 10 scores. (Contains 1 table.)