Grading Explanations, Spring 2016

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Grade parts

There were 11 full-length labs, and lab 12 which had two parts. Thus, there were 35 lab parts (11 labs of 3 parts each, plus one lab of 2 parts). Lab 5 had the AVL tree worksheet, which counted as 4 more points. So the total number of points for the labs was 35*10+4 = 354. Labs counted for 45% of the final course grade.

Each midterm counted for 15% of the final course grade, even though the total number of points on each midterm was different. The final counted for 25% of the final course grade.

The grade breakdown (how much each part counts for the final grade) is as listed on the course syllabus (md).

Particiation grade

As stated in the course syllabus and at the beginning of the semester, there was no participation grade... :-(

Grade curves

The grades on the midterms were relatively high that we did not give an explicit curve on the midterms. However, they were not exactly in the range we aim for (low 80's), so we took this into account when considering the course curve (below).

Rounding

Yes, we round grades. Note that round(x) == floor(x)+0.5. So we added 0.5 points to everybody's curve to take into account rounding. Note that this means rounding is already taken care of, so if you get an 89.9999999999999999999, it's still a B+, no matter how many times you ask - you don't get to round a second time (in reality, it was an 89.49).

Course curve

The curve so far is 0.5 from rouding. We raised that up to 5.0 for the final course curve. Thus, everybody got 5 points added to their average (your average being what the gradebook reports). Note that this already includes rounding, so you don't get to round a second time!

Grade breakdown

As stated at the beginning of the semester, each 10-point "decade" is a separate letter grade range (60-70 is a D, 70-80 is a C, etc.). The exact ranges, taking into account the course curve mentioned above, are below. Note: the following table ALREADY includes the course curve! So you take your exact average from the gradebook and see where it lies on this table. And rounding has already been taken into account (see above), so you don't get to round a second time.

Minimum course average Letter grade
50.0 D-
58.0 D
62.0 D+
65.0 C-
68.0 C
72.0 C+
75.0 B-
78.0 B
82.0 B+
85.0 A-
88.0 A
95.0 A+

Note that the A+ range and the D- range follow a slightly different pattern. The A+ range is a percentage of the class (in this case, the top 7 course averages), and thus ended up being 95.0. The D- range extends down a bit more.

Permanent record

We've enabled the (terrible) Collab gradebook tool, and imported all the grades into there where they will live for all eternity. Or at least until UVa doesn't feel like keeping them around any more...

Regrade statistics

For the spring 2016 semester, there were 9,391 lab grades assigned throughout the semester: about 264 students times 35 lab parts is 9,240; the difference was from students who dropped or withdrew from the course. There were 279 regrades that were submitted (3.0% of the graded assignments). Of those, 27 were due to extensions, and 70 more did not have any grade change. Thus, there were only 279-27-70 = 282-56-64 = 182 regrades where a grade was changed. That is only a 1.94% error rate.