First, the educational community is not solely responsible for all of society's woes. Second, the educational community IS responsible for getting a child to progress and demonstrate measurable gains. Although Sanders does not completely discount the fact that a student's socioeconomic environment may affect his or her achievement levels, he puts no trust in data that's manipulated by differences in student backgrounds. You simply can't forecast the effect of a school by its mailing address. You're not stuck with what you're born with.
Students can still move from low to higher distribution gains on the scale.
It's just harder when you have a series of bad instructors. Still other data suggests that teachers tend to increase their effectiveness during their first ten years of employment. Following their initial ten years, teachers tend to even out and eventually decrease in effectiveness. The whole point of conducting these measurements is so that we can shrink this type of variability. Whatever the differences, we've got to measure and assist teachers in being more effective.