Are standardized tests a helpful way of evaluating schools? Charles Murray in The New York Times argues that they're not. He's responding to a study that seems unfavorable to "most advocates of school choice." The study shows that students from charter schools don't necessarily have markedly different "achievement growth rates" from students in regular schools.

"Let's not try to explain [these results] away," suggests Murray. "Why not instead finally acknowledge that standardized test scores are a terrible way to decide whether one school is better than another?" Education experts have known for a while that charter schools don't look so great in test-score comparisons. But "the reason for the perpetual disappointment is simple," says Murray: "Schools control only a small part of what goes into test scores." Instead:

Cognitive ability, personality and motivation come mostly from home. What happens in the classroom can have some effect, but smart and motivated children will tend to learn to read and do math even with poor instruction, while not-so-smart or unmotivated children will often have trouble with those subjects despite excellent instruction. If test scores in reading and math are the measure, a good school just doesn't have that much room to prove it is better than a lesser school.
Murray uses this argument to get to one conclusion: school choice for him isn't about results, but about having his children children "taught the content that [he] think[s] they need to learn, in a manner that [he] consider[s] appropriate." Are test scores a poor measure because they miss what truly makes schools different?