What's old is new again:
In Zen and the Art of Motorcycle Maintenance, Robert Pirsig mentions his own experiment in withholding grades at a university. He didn't just announce on the first day that everyone would get an A+ (that seems gimmicky), but since it was a class on rhetoric, he spent the course developing an argument for eliminating the grades-and-degrees system and discussing it with his students. Most students were unenthusiastic or opposed -- grades and degrees are what they came for.
He assigned, collected and graded papers but returned them to students with only the comments, not the grade.
- A-students were annoyed, but did the work anyway
- B-C students blew off some assignments
- C-D students usually skipped class
He observed this and changed nothing. If students acted up, he let it slide.
Around 3-4 weeks into it:
- A-students got nervous and pushed themselves harder, in class and in papers
- B-C students saw what the try-hards were doing and returned to the usual level of effort
- C-D students who had committed to ditching would occasionally show up out of curiousity
- A-students relaxed and began enjoying the class as active participants. In a final essay, still not knowing what their grades were, these students favored eliminating grades by 2-1.
- B-C students saw this and freaked, putting an unusual amount of effort into their work. Eventually, they joined the A students in engaging class discussions. These were evenly divided over the issue of eliminating grades.
- C-D students, or those who attended, also saw this and began trying to hand in reasonable work. Those who couldn't hack it freaked even more, and remained in a state of Kafkaesque terror until the quarter mercifully ended. Naturally, in the final essay these students were unanimously opposed to eliminating grades.
Interesting as this result was, he reverted to the regular grading system the next quarter because he couldn't provide any alternate goal for students -- those who can recognize quality in their own work don't need the university; those who can't need something to work toward, or they don't progress.