If we accept the premise that tests cannot measure learning, what would a legitimate use be?  It turns out that how we understand the purpose of testing is a window into the more fundamental question of what we think schools are for.

The lure of the false positive for a student is that it seems quicker to cram for a test and get a high score than to actually learn the material.  If a student is doing school, a false positive counts as much as a true one;  the goal of school for him is to get good grades, and a test score isequally valid whether it represents genuine learning or not.  Unfortunately, this point of view is truly pervasive.

What a teacher wants is for students to have true positives, that is, high test scores that occur because of solid understanding of the material.  Unfortunately, in my experience many teachers aren’t aware of the existence of false positives, or can’t or won’t distinguish between true and false positives.  Their response when students do badly on a test is to try to help them raise those scores.  This can happen while still remaining blind to the difference between true and false scores.

The question we should be asking is not how to raise low test scores, but how to make the learning process so effective that high test scores actually mean something.  Even more importantly, we need to see whether test-taking can become a meaningful, even an essential part of the learning process.

As shown at the start of this chapter, low test score can be re-imagined as important feedback on what a student still needs to learn.  In educational jargon, these are called formative tests.  That is a very different purpose than when tests are considered results that occur at the end of a unit.  These are called summative tests, and they serve little purpose in the learning process.  They do serve another purpose which, as we shall see, leads to a number of unspoken consequences that have serious negative effects on students and how they learn.