We have reached a point in our public life where the only way to demonstrate the success of a school is to say it has higher test scores than some other school. But we all know–or should know–that there are many ways to get higher test scores without having a better school.

Some schools get higher test scores because they have a selection mechanism. The selection mechanism might be as simple as a test for entry. That screens out low-scoring students. But no one would be so brazen as to say that an exam-entry school was therefore better than an open-admission school.

But there are more subtle ways to get higher scores. Another is to have a lottery for admission. That means that parents must fill out papers to apply for admission. That screens out parents who don’t have the knowledge or the motivation to fill out an application.

Another way is to limit the admission of special-education students because your school doesn’t have the personnel or resources to help them. That screens out students who might present problems, require expensive trained staff, and possibly have lower scores because of their disability.

Another way is to have a high attrition rate and not to admit new students as current students leave the school. The ones who leave are likely to be those who are having trouble meeting the academic demands of the school or who are in trouble because of breaking school rules. That means that each successive class is smaller and more compliant and likelier to have higher grades.

Another way is to accept few or no students who are English language learners. That helps raise the school’s test scores.

Another is to have more money to spend on smaller classes, on intensive tutoring, and on other things that produce higher test scores.

In a blog for CNN, Gary Rubinstein identified the many kinds of cheating that are now being employed to inflate schools’ test scores: http://schoolsofthought.blogs.cnn.com/2012/04/12/my-view-the-other-types-of-cheating/.

Some researchers believe that the best way to measure the performance of students who enter a charter lottery is to compare the scores of those who won the lottery and those who lost. That is widely trumpeted as “the gold standard” of research, but even this method has a defect. The ones who win are enrolled in a small school with small classes, the latest technology, and peers who are equally motivated. The ones who lose the lottery are likely to enroll in the neighborhood school with larger classes, obsolete technology, and peers who include students who are unmotivated, as well as peers with disabilities and peers who are just learning English. So, this is by no means a fair comparison since the two groups of students will have access to unequal resources and opportunities.

So, I am left with the view that we need a far better way to describe successful schools. Test scores alone are not the way. They may define a school where students spend every day engaged in test prep. They may describe a school producing compliant student-robots.

We need better definitions of success. We need a far more thoughtful way of educating the future generation.