What's a “good” grade as far as students are concerned? What's a “bad” grade? Are some grades “neutral” and cause neither disappointment nor pride? Where's the cutoff for good grades and the starting point for bad ones? In the study referenced below, researchers solicited data from students regarding their perceptions of grades.
As the researchers note, not much research to date has addressed this question, although research has explored a number of related areas. We know, for example, that faculty and students agree that grades should be based on performance, but students believe that effort should also count. Some faculty are open to considering effort in grade calculations, but faculty and students do not agree on the extent of studying that should qualify as effort worth counting. In one study (cited in this research) faculty estimates of study time required to count as strong effort were nearly twice as much as the estimates offered by students.
In this study, involving more than 500 undergraduates enrolled in a general psychology course, students rated both alphabetic grades (A, B, C, etc.) and numeric grades (4.0, 3.0, 2.0, etc.) and the plus and minus iterations between these grades in several different conditions. They used a 10-point scale to evaluate the worth of each grade. They were not evaluating grades they had actually received but grades given to hypothetical persons.
“The most interesting finding in this study was that students' categorical perception of grades tends to be very simple. … The grades that college students receive are either ‘good' or ‘bad,' and there is absolutely nothing neutral about it.” (p. 258) The cutoff point for good grades was between B- and C+ when students rated the worth of alphabetic grades. It was a bit lower for numeric grades.
Is there a problem if students think so categorically about grades? Most of us would say yes. We've had not very well-prepared students who, through great effort, manage to earn a C. That's an accomplishment that shouldn't satisfy them, but often it's a source of pride. When the student has tried hard and still gotten what they consider a bad grade, they can conclude they won't ever be able to do better and give up. Some of us have had particularly grade-concerned students who want to retake courses in which they've earned B's because as far as they're concerned that's a bad grade.
Bipolar thinking about grades adds an emotional dimension that makes grades even more important than they already are. The good or bad assessment is so all-encompassing it's an easy leap from good or bad grade to smart or dumb person. Much other research has established that students strongly associate performance with natural ability. If you're smart, you get good grades and you mostly do that without much effort because you've got these natural talents. If you don't possess these natural abilities, chances are good you'll get bad grades whether or not you expend much effort.
Teachers need to work on helping students see grades in a more nuanced way. They are measures of learning, often portraying inaccurately or incompletely what a student knows and can do. They are never measures of the worth of a person nor do they predict what any individual learner can accomplish. All this is easy to say, but changing student beliefs about what grades “mean” takes patient, persistent efforts at persuasion.
Reference: Boatright-Horowitz, S.L., and Arruda, C. (2013). College students' categorical perceptions of grades: It's simply “good” vs. “bad.” Assessment & Evaluation in Higher Education, 38 (3), 353-359.