Why grading sucks, and what to do about it

Modified ungrading can help both professors and students

Most professors would rather wash walls than grade a pile of blue books (or an inbox with 39 papers). Students worry about grades when they turn in assignments, and react with feeling when they receive them. Grading is fraught with emotion on both sides and seems to have little to do with learning. Are grades necessary? Does marking student work with a D or an F do harm, creating a toxic environment? And if it does, what should we do?