Decades of research shows that grades diminish students' interest in whatever they're learning, discourage students from taking academic risks, and reduce the quality of students' thinking, writes Kohn. Contrary to what many people assume, grades are not necessary to promote achievement. Attempts to "improve" grading--such as standards-based grading--do not address the fundamental problem because these approaches are based on "the simplistic premise that it's always good to have more data," and that "learning can and should be broken down into its components, each to be evaluated separately." Kohn argues that much of the most important learning cannot be measured quantitatively. He provides examples of teachers who have successfully jettisoned grading in favor of narrative assessments and meaningful feedback.