Students in these seven different classes took the test at the beginning of the semester. Perhaps not surprisingly, they didn’t do very well (though many of them had already taken high school physics; Hestenes and Halloun expected them to do better).
The students took the test again at the end of the semester. And they still didn’t do very well. Their scores went up by only about 14 percent, meaning that, after an entire semester, they understood only about 14 percent more about the fundamental concepts of physics than they had at the beginning.