These percentage cutpoints for letter grades certainly sound quantitative and precise. Can anyone follow them up with some sort of logical support for using these particular cutpoints as opposed to others? As Paul Brandon aptly asked, "By what criteria of knowing?" If you have a conceptual definition for each letter grade (e.g., A=Outstanding achievement, B=Very good,commendable,C=Satisfactory, D=Minimal), how do you get from a point score on a test to the corresponding letter grade? Isn't it necessary to consider the difficulty of the assignment, type of academic skill required, preparation of students by the instructor, etc. before deciding on the minimum percentage of points possible to use for assigning each letter grade? Consider: When I give my students a test composed of difficult items, nobody gets 90% of the points possible. Does that mean that nobody is "outstanding" (as in "standing out from the group" in relative performance)? And if the test is composed of fairly easy and predictable items, perhaps a third of the class will answer 90% correctly -- does that mean that a full third of the students deserve to be recognized as outstanding? Note that their grasp of the course material is the same under both scenarios -- what is different is (1) the difficulty of the items on that particular test, and (2) the proportion of the group getting 90% of the possible points. At this point, I just don't see a justifiable reason to apply an institution-wide "percentage of points possible" for course grading. It makes no psychometric sense to me. Perhaps someone can correct my understanding on this issue. --Dave
----- Original Message ----- From: "Michael Smith" <[email protected]> To: "Teaching in the Psychological Sciences (TIPS)" <[email protected]> Sent: Sunday, January 11, 2009 10:17:32 AM GMT -08:00 US/Canada Pacific Subject: Re: Grading Guidelines...Was [tips] Weighty problem We have the rather fine-grained: A+ 95–100 A 90–95 A– 85–90 B+ 80–85 B 75–80 B– 70–75 C+ 65–70 C 60–65 C– 56–60 D+ 53–56 D 50–53 F 0–49 Phew! --Mike -- ___________________________________________________________________ David E. Campbell, Ph.D. [email protected] http://www.humboldt.edu/~campbell/psyc.htm --- To make changes to your subscription contact: Bill Southerly ([email protected])
