21-122: Mid-Semester Grades

I've finished assigning mid-semester grades, and I wanted to take a moment to describe exactly how that was done. As you know, your midterm exam average accounts for 60% of your grade, and your homework average for 15%. I've computed a numerical average for each of you using the following formula:

Avg = ( .60*[Exam #1 Grade] + .15*[Homework Average] )/(.75)

So your exam score counts for (60/75)ths of your grade, and your homework average counts for (15/75)ths. Then I computed grade cutoffs for these averages, by averaging the grade cutoffs the same way I computed your averages, i.e.

X-cutoff = ( .60*[Exam #1 X-cutoff] + .15*[Homework Average X-cutoff] )/(.75)

where X may be A, B, C or D. To assign +/- grades, the B and C ranges were divided into thirds, and the A and D ranges were divided in half. (There is no A+ and no D- grade.)

One final comment: As I was entering the final grades this afternoon, I realized I had made an error when calculating grades yesterday that systematically raised peoples averages a bit. I've corrected for this, and so some of you who saw your grade yesterday may notice it has gone down one increment (in a small number of cases more). I apologize for this apparent downgrade, but I want to make sure your grade represents where you really stand in the course.