The basic grammar of schooling, like the shape of classrooms, has remained remarkably stable over the decades. Little has changed in the ways that schools divide time and space, classify students and allocate them to classrooms, splinter knowledge into "subjects," and award grades and "credits" as evidence of learning.

Continuity in the grammar of instruction has puzzled and frustrated generations of reformers who have sought to change these standardized organizational forms. In this chapter we ask how this grammar came about, why it was so tenacious, and why even vigorous and imaginative challenges to it tended to fade, leaving behind a few new practices here and there but not fundamentally altering the way schools are organized for instruction.