Schinske and Tanner highlighted the fact that grades were developed as a method for universities to communicate (e.g., between schools). This is still an important function that grades play today (within/between schools, and beyond), and there are clear benefits from having a valid, reliable grading system. In the early 20th century, percentage (100-point) scales were frequently used (Cureton, 1971). The letter grade system adopted at Harvard was apparently a result of faculty members’ concerns about the reliability of grades measured on a percentage scale, and it was believed that a letter grade system (with 5-categories) would provide increased reliability.
Even today, issues with reliability (as well as validity) of grading exist. (Schinske and Tanner discuss this as well.) Thus, I found it a bit surprising last fall when the University of Windsor (where I currently teach) switched from a letter grade/point system (a 13 point scale) to a percentage system for final grades. I could understand if this shift were bringing the school’s grade reporting in line with many others in the same region (e.g., within a province or country); with different grading systems/scales used by various universities, it can be challenging to make comparisons between students from different schools for things like scholarships, professional school applications, etc. However, from my observations (and the OMSAS Undergraduate Conversion Chart), the percentage system isn’t the most widely used grading scale in Ontario, nor across Canada.
I’m not sure why the change to a percentage grade system was made. It is possible that the rationale was provided in some form, but that I didn’t receive it, or have overlooked it. I’ve asked colleagues here, who also didn’t know. Some (quick) searching of the university website hasn’t pulled up anything helpful, but again, it could be there and I’m not finding it (as my search terms are pretty common words on a university website). Although I’ll be a bit embarrassed if someone posts a link to something that explains it, I’d still appreciate knowing!
A few questions come to mind: Why did this university change from letter grades to percentages? Is this something that has happened at other institutions? Are there schools that have recently taken the opposite approach (moving from percentages to a point system)? (From the OMSAS chart, I’m guessing that Dalhousie and the University of Toronto made changes, but I don’t know in which direction.) Have any changes in grading systems/scales been accompanied by initiatives relating to how grades are determined?
As ever, I’m interested in seeing your comments (and, hopefully, answers to some of my questions)!
Cureton L.W. 1971. The history of grading practices. NCME Measurement in Educ. 2(4):1-8. Link to pdf.
Schinske, J., and Tanner, K. 2014. Teaching More by Grading Less (or Differently). CBE-Life Sciences Education 13(2): 159-166.