Letter grades are a tradition in our educational system, and we accept them as fair and objective measures of academic success. Jessica Lahey writes in The Atlantic that: “If the purpose of academic grading is to communicate accurate and specific information about learning, letter, or points-based grades, are a woefully
blunt and inadequate instrument. Worse, points-based grading undermines learning and creativity,rewards cheating, damages students’ peer relationships and trust in their teachers, encourages students to avoid challenging work, and teaches students to value grades over knowledge.
“Letter grades communicate precious little about the process of learning a given subject. When a child earns a ‘B’ in Algebra I, what does that ‘B’ represent? That ‘B’ may represent hundreds of points-based assignments, arranged and calculated in categories of varying weights and relative significance depending on the a teacher’s training or habit. But that ‘B’ says nothing about the specific skills John has (or has not) learned in a given class, or if he can apply that learning to other contexts. Even when paired with a narrative comment such as, “John is a pleasure to have in class,” parents, students, and even colleges are left to guess at precisely which Algebra I skills John has learned and will be able to apply to Algebra II.
“As a teacher, I struggled with the fuzzy logic of grading every term. I was invested in all those points I totaled and calculated, in categories I devised and weighted on assessments I wrote. I considered their relative value, their worth as a measure of learning, their objectivity and subjectivity. Did I grade that first paper, the one I graded just after dinner, when I was fresh, full, and in a good mood, on the same relative scale as that last paper, when I was exhausted, and just wanted to get to bed? Did the midterm test comprehension or rote memorization? I agonized over these details as if they were my final and unequivocal communication of educational truth.”
More at: http://www.theatlantic.com/education/archive/2014/03/letter-grades-deserve-an-f/284372/