There is a single proctoring and grading pool for Trad GTAs, which means you’ll be grading both 2211 and 2212 tests regardless of which class you’re TA’ing for. GTAs who are first year grad students don’t grade final exams (because you have your own finals to worry about!).
The tests are typically 40-50% multiple-choice which you don’t have to worry about grading. The rest of the test usually has 3 free-response problems, and those are the ones that you’ll be grading.
The Trad Grading Rubric
When grading exams, Jarrio/Murray will provide you with a Grading Rubric which you will follow when grading free-response exam problems. They will go over the rubric in great detail with you in the first exam grading session, but in general terms there are four types of errors and six possible scores for each problem:
- Full credit — this is earned when a solution is perfectly correct. This includes both procedure and final answer, including the correct units where needed.
- Procedural error — for example, something that was correct but suddenly turned incorrect in the final result for no apparent reason; obvious calculator errors like using radians instead of degrees; missing units from a numerical answer; written units in a symbolic answer.
- Minor physics error — for example, using sine instead of cosine of an angle when decomposing a vector into components; using the formula for moment of inertia of a point mass instead of the one for a solid sphere when calculating angular momentum.
- Major physics error — for example, using conservation of energy in a problem that should have been solved with Newton’s second law; using Gauss’s law in a problem that needed Ampere’s law.
- Minimum progress — if the student’s solution is utterly wrong but there’s at least some kind of effort that demonstrates a slight bit of understanding, so the solution doesn’t quite deserve a zero.
- No credit — when a problem is left blank, or where just an answer was written with no work shown, or if the student wrote something completely irrelevant.
The differences between the various types of error can sometimes be subjective, and sometimes it depends on what exactly the problem is asking for. For example, a missing minus sign could mean the student simply forgot to carry it over, making it a procedural error, or it could mean a fundamental misunderstanding of how to determine the direction of the magnetic field caused by an electric current, making it a major physics error. It is therefore extremely important for all graders to agree on what penalty to give for an error, to ensure consistency in grading. If you have doubts on what penalty to assign to an error, ask Jarrio/Murray, or post on the Slack channel.
Beware of Propagation of Error! An error in a problem should be penalized only once. For example: a student makes a mistake in part (a) of a problem, and they get it wrong. The result from part (a) is then used in part (b). The student has the procedure perfectly correct in part (b) but because they used their incorrect result from part (a), their answer for part (b) is wrong too. In this case, you take the points off from part (a) but award full credit in part (b). If you took points off for part (b) as well, you’d be penalizing the same error twice in the problem, which should not be done.
Grading Trad Exams
The Trad exams are graded electronically, through Gradescope. A day or two after each 2211 and 2212 exam, after all the exam papers have been scanned, all the GTAs will be informed that grading is now open, and Jarrio/Murray will provide you with a list of grading assignments (either via email or in the Slack channel) — meaning, what specific problem and across which specific exams each person will need to grade.
Jarrio/Murray will also provide you with the solution key to the exam. Make sure to read through it and familiarize yourself with the problem(s) you’ll be grading. If anything is unclear, post in the Slack channel.
How long does it take to grade exams? You should be prepared to budget 2-3 hours for grading. Whether you do it all in one sitting or in bursts is up to you, so long as you finish grading by the deadline given to you by Jarrio/Murray (usually 3-5 days after the exam).
The week after the exam, the Recitation GTAs need to pick up the graded exams for their sections (from the same place where they pick up the worksheets) to hand back to the students during the next recitation meeting.
How to use Gradescope
Please watch the video below.