In the Times, Susan Engel, director of the teaching program at Williams College, tears into our current obsession with standardized tests in education:

As children, teachers and parents sprint, slink or stumble into the new school year, they also find themselves laboring once again in the shadow of standardized tests. That is a real shame, given that there are few indications that the multiple-choice format of a typical test, in which students are quizzed on the specific formulas and bits of information they have memorized that year, actually measures what we need to know about children’s education.

Instead of punishing students with tests built around little bubbles and no.2 pencils, Engel argues that it's time to pioneer a new generation of tests that "truly measure the qualities of well-educated children". We should stop trying to quantify rote memorization and instead focus on the intellectual skills that actually capture the virtues of education. Engel describes these talents as:

...the ability to understand what they read; an interest in using books to gain knowledge; the capacity to know when a problem calls for mathematics and quantification; the agility to move from concrete examples to abstract principles and back again; the ability to think about a situation in several different ways; and a dynamic working knowledge of the society in which they live.

If only. It really is hard to quibble with the testing aspirations outlined by Engel. Who wouldn't embrace a test that could measure these critical thinking skills? Who doesn't want to do a better job of testing comprehension, and not just memorization? Who doesn't want little kids to love books? The hypothetical tests Engel describes make our current obsession with multiple choice exams seem shallow and callous, like some vestigial legacy of the 19th century schoolhouse.

And yet, I'm going to quibble. But before I quibble let me make a few things clear. Firstly, I have no intention of defending everything about NCLB. Secondly, I'm not suggesting that the tests we employ right now don't need drastic and dramatic changes. That said, I think Engel's op-ed misrepresents the real function of these multiple-choice tests. (In fact, I think the tests themselves misrepresent their real function.) We pretend these exams measure explicit knowledge, that the math tests capture the mathematical facts stored inside the hippocampus, and that the history tests reflect all those names and dates we will never forget. But that's all wrong.

Let me tell you a story about organic chemistry. On the first day of class - I was a sophomore, surrounded by anxious pre-med majors - the professor announced that we would soon forget everything we were about to learn. He assured us that, no matter how hard we studied, all of these chemical equations would vanish from our memory. Why, then, were we taking the class? According to the professor, organic chemistry was really about learning how to learn. In a sense, he wasn't testing our chemical knowledge - he was testing our ability to stuff lots of peculiar facts into our head, to cram for weeks for a curved exam. And this is why the class was a requirement for medical school. It was a way of weeding out the students who didn't have the discipline, who lacked the grit necessary to stay up late staring at notecards about nitrogen.

The same lesson applies to the tedious exams of grade school. We're not really testing the knowledge of students, since all this knowledge will soon be forgotten. (As promised, I forgot all my organic chemistry the day after the final.) Instead, we're measuring their ability to learn, to sit in the chair and stare at the blackboard and listen to the teacher. A 5th grade science test isn't a test of science - it's an indirect test of all sorts of essential mental habits, such as self-control, grit, conscientiousness, and executive attention. Furthermore, there's an ever-growing body of evidence that these psychological traits are incredibly important for success in the real world. While society has long obsessed over raw smarts and intellect – just look at our fixation on IQ scores – it's now becoming clear that our dispositions are often more important. A recent paper by James Heckman and Flavio Cunha, for instance, notes that dependability is the trait most valued by employers, while “perseverance, dependability and consistency are the most important predictors of grades in school.” Of course, these valuable skills have little or anything to do with general intelligence or abstract reasoning or critical thinking. And that’s probably a good thing, since the available evidence suggests that these traits are much more malleable, at least when interventions occur at an early age. Our education might not make us much smarter – alas, our IQ is strongly shaped by our genes – but it can make us a better person, and that’s even more important.

This returns me to the multiple choice tests mandated by recent educational reforms. Yes, they are tedious. Yes, they are depriving students of all sorts of important extra-curricular activities. Yes, they are reducing the creativity of teaching. Yes, they are, at best, a deeply flawed compromise. But I'd argue that these tests are also, at the very least, a mediocre way to measure the mental skills that really matter. Because long division isn't really about long division, and organic chemistry isn't really about organic chemistry. It's about indirectly teaching the admittedly old-fashioned traits (such as grit and self-control) that will persist long after we forget all the facts. This is what the KIPP schools do. They are effective because they explicitly emphasize the fundamental habits that matter. Dave Levin, a co-founder of KIPP, told me last year about a KIPP school that gave every kid a t-shirt with the following slogan: "Don't Eat The Marshmallow". Needless to say, these skills are especially important for at-risk children, as demonstrated by this recent study linking test scores to the self-regulation of behavior. The kids who scored higher on measures of self-regulation also scored higher in every subject area.

And this is why I'm a bit suspicious of tests that focus on abstract intellectual talents, such as critical thinking, or the "ability to think about a situation in several different ways". What I'd love to see instead are tests that more accurately measure the traits and habits that really matter. Instead of using algebra to indirectly quantify grit in the classroom, why not figure out a way to test it straight? Instead of using spelling to measure self-control in second graders, why not find a way a more precise measurement? The real hope, of course, is that such tests would lead us to focus on developing the classroom techniques that can really give our kids the mental tools of success. Because knowledge is fleeting. Knowing how to think and behave is what endures.

Update: Just to be clear: I'm not endorsing our current system. In some respects, we've got the worst of both worlds right now, since we're testing the traits that matter inefficiently (through tedious drills, etc.) and also managing to stifle intrinsic motivation. But I think if we're going to reform our system then we have to begin by focusing on the variables that seem to really matter in real life, when all the multiple choice tests are over.