History of Grading

Robert actually has found a real answer to your question Greg:

Here are the URLs for a couple of articles on the history of grading –

http://www.indiana.edu/~educy520/sec6342/week_07/durm93.pdf

http://academics.holycross.edu/files/Education/schneider/Making_the_Grade_JCS_pre-pub.pdf
An interesting comment from this article: … Prussian schools organized children and the curriculum in terms of a series of stepped grades that allowed students to move along at their own pace while increasing the overall efficiency of the system. The original idea of grade levels was to allow students to move at their own pace, not keep them in lockstep with one another.

http://www.slate.com/articles/news_and_politics/explainer/2010/08/e_is_for_fail.html

http://www.be.wednet.edu/cms/lib2/WA01001601/Centricity/Domain/18/SBG/EL13%20Percentage%20Grades.pdf
According to this article, the current percentage grade system is a late development and the result of increased reliance on technology (computers). In addition, The 100-point scale that teachers employed in the early 20th century was based on an average grade of 50, and grades above 75 or below 25 were rare. … In contrast, most modern applications of percentage grades set the average grade at 75 (which translates to a letter grade of C) and establish 60 or 65 as the minimum threshold for passing. This practice dramatically increases the likelihood of a negatively skewed grade distribution that is “heavily gamed against the student” …

Some definite food for thought here.