"Schools sought to achieve greater efficiency by making classes as academically homogeneous as possible; it was argued that students who achieved at the same level could work at the same pace, proceeding rapidly and uniformly through the material to be covered under the teacher's supervision. High-ability students would not be held up by students who were slower, and lower-ability students could receive specialized instruction that would allow them to catch up with their peers later on."

"In general, researchers have found that students assigned to general or vocational tracks are exposed to less-demanding academic curricula than students assigned to college preparatory tracks. In the lower tracks, students participate in lessons that are more often basic skills-oriented, segmented, and simplified; these learning opportunities seldom elicit the kinds of critical thinking and sustained engagement demanded by more complex academic work. Furthermore, in the lower tracks, teachers tend to manage their classrooms differently, demanding conformity to external rules rather than appealing to students' internal motivations and the intrinsic rewards of learning, as they tend to do with higher-track students." (Policy Studies Associates, 1995)