# Students using the same flawed online solution sheet as the grading TA

I am in a small electricity and magnetism class, and I have recently become aware of other students using an online solution sheet (on slader.com). On the most recent homework, I (who didn't use the online solution sheet) got a significantly worse grade than I expected. When I read the TAs posted solutions, I realized that he had made all of the same mistakes (the primary one being assuming that the parallel impedance formula is 1/(Z_1)+1/(Z_2) when it is actually 1/(1/(Z_1)+1/(Z_2))) and all of the exact same approximations as the online solution sheet. It is clear that he basically copied from the online solutions. What's worse, he marked many of my solutions wrong: both the ones where I had different (more accurate) approximations and the ones that were correct, but different from his incorrect solutions (the professor confirmed that my solutions are correct).

I'm guessing it isn't against the rules for a TA to use an online solution sheet, but the fact that he has been using the same one that many of the students are using means that this entire semester I have been at a significant disadvantage. I have done well, but the class is curved so there's that also.

If the online sheet is incorrect and you suffered because of it, and if you have proof that the TA used that sheet, then you should point out to the professor of the course what has happened.

But, ask for a a comparison between your answers and those that the TA suggests. This will make it clear. The other students may suffer or not, but that is up to others. You have a right to a correct evaluation of your work and the professor should be made aware of online solutions - especially if they are incorrect and misleading students.

One set of students getting credit when they've broken rules and other students suffering when they have done the correct thing is the worst outcome possible.

You don't need to accuse anyone. Point out the online sheet. Point out the (matching) solution rubric. Show your own work and ask for a fair evaluation.

• Let's pass over the issue of a TA needing to use an online source for an elementary formula like this. It's about the same as a math TA needing a calculator to check that 2+3=5 IMHO. Dec 11, 2019 at 14:39
• @alephzero, perhaps, but it might just be an issue of convenience. If the scale of work is large, shortcuts are likely to be taken. And things are more likely to be missed. But I do think the TA shares some fault here, so the solution lies with the prof, not the TA. Dec 11, 2019 at 14:43
• @alephzero that has nothing to do with the answer, or the question Dec 11, 2019 at 18:13
• @Buffy You have far too much faith in professors. He or she will no doubt assume that OP is just arrogant and entitled and decline the request for remarking at face value. But going to the TA is useless too because they will want to hide their mistake. It goes without saying that the students will regard OP as a traitor. Some situations simply don't have any remedy. OP should channel his or her efforts into something else - there are plenty of things to fight for - personally and otherwise - once you realise that the world is not inherently a safe or fair place. Dec 12, 2019 at 18:16
• @user234461 and you seem to have too much cynicism and distrust in professors. Not to mention that, it is far more likely than not that if there is a problem with their course which is likely to tarnish their reputation, they would really want to hear about it. Dec 13, 2019 at 10:32

First and foremost, the issue here is that your correct answers were marked as incorrect, a manifest injustice. That must be rectified. Of course, the reasons why it was marked as incorrect are relevant, but do not let their legitimacy or otherwise distract from that basic fact. People marking work do sometimes make mistakes, even if competent. But that does not change the fact that you are entitled to have your work marked properly.

In your case, it sounds like the person marking your work got it badly and objectively wrong. You should use whatever appeal mechanism exists to have the work re-marked by someone else. If that does not rectify the unjustly low mark (and the unjustly high marks of others), you should complain higher up.

• FWIW, I got completely lost trying to solve a problem in Jackson (graduate physics E&M) & made up a fake solution full of "...and that leads to an expansion of the form..." , and the senior grad student TA gave me full credit! I guess he didn't understand E&M any more than I did. Dec 12, 2019 at 12:32

The first thing to do would be to convince the TA that indeed, he's made a mistake in grading. This includes all the examples you gave: that he has been using the wrong parallel inductance formula, that your approximations were better, etc. I would try to arrange a face-to-face meeting for this, since it's much easier to communicate your points then (especially since it sounds like you'll need to write formulae out).

If you manage to convince the TA I expect that he will sort out the rest, either by adjusting your grade up or adjusting everyone else's grade down.

As for the online solution sheet, there's a good chance the TA (and the professor) will be interested in knowing it exists, especially if it's being used by students & if it is incorrect. I would mention this too, but if he elects not to do anything about it it's not something to fight over. Your priority is to learn, and you're doing that; it's much less your concern if the other students aren't learning.

• If I'm 'learning' and getting a 2.0 and other student's are 'not learning' and getting 3.0+ ... it's not my concern? Dec 11, 2019 at 15:41
• Regarding the comment about other students not learning, for many students university is a competition of who's gonna get the best job after graduation, and that's usually related to who's getting the best grades. So if you're getting lower grades than people who should be getting lower than you it very much affects you. This effect is even worse if the professor "curves" the grades. Dec 11, 2019 at 16:01
• @AlexandreAubrey "for many students university is a competition of who's gonna get the best job after graduation" the professor may not see it this way and a university or professor has no academic ethical requirement to consider it. Dec 11, 2019 at 21:05
• @crasic the professor doesn't have to do anything about it, but telling OP that other students' grades don't matter isn't true and I explained why. Dec 12, 2019 at 15:00
• @crasic Regardless of the "competition to get the best job," the prof does have a moral obligation to rate student's knowledge and skills correctly: others without the knowledge or time to do this directly (such many people hiring for jobs) rely on professors' evaluations. Especially in engineering, where the students may later end up working on safety-critical systems, it's a disservice to society to misrepresent people's level of skill.
– cjs
Dec 13, 2019 at 0:34

There is an underlying problem that in the era of chegg and slader, it's ridiculous to assign problem sets as high-stakes work, as your professor is apparently doing. People's grades should be based on tests, not homework. In my physics classes, I've recently reduced problem sets from 10% of my students' grades to 1%, because otherwise I either had to ignore the cheating or spend all my time being a cop and calling people on it when they all turned in the same solutions copied from chegg. (I teach at a community college, so there is no TA.)

Actually, you could count yourself as lucky that you're at a school where undergrads do get human feedback on their problem sets in lower-division classes. For most lower-division STEM classes these days, people just use online systems like MasteringPhysics or MyMathLab, and no human ever looks at the students' papers. When used in conjunction with high-stakes grading (like making problem sets 20% of the students' grades), this type of system is basically a perfect storm of conditions for creating and encouraging cheating.

A lot of my colleagues persist with this type of setup because they see it as an arms race. They're afraid that if they don't give homework a lot of weight, students will concentrate their efforts on problem sets for other classes.

So IMO the person who's really messing up here is the prof who set up the structure of the class. Even with a more conscientious TA, the structure is just a perfect setup for creating and rewarding academic dishonesty. I would suggest dealing with this by (of course) complaining to the prof about the TA, but also complaining to the prof about the structure of the course, and commenting on this on the prof's evaluation of teaching, if one is administered to your class this semester.

• If you are teaching somewhere where students turn in homework if it is only worth 1% then you are in a relatively privileged position. Not everyone is similarly situated. What would you suggest somebody do if 90% of students won't do any homework unless it is worth at least 15-20%? Of course, you can let them fail. But judging somebody as complaint-worthy for making a different call is sheer arrogance. (I have taught in both kinds of places and there is no one-size-fits-all right answer here either pedagogically or ethically.)
– cfr
Dec 12, 2019 at 5:17
• "People's grades should be based on tests, not homework." In upper-division physics classes (which is apparently the situation here), the types of problems appropriate for a homework assignment are vastly more involved than those that can be given on a test.
– cag51
Dec 12, 2019 at 6:07
• @cag51 that's what we call a "take-home test" . It's not in the same category as the level of problems indicated by the OP. Dec 12, 2019 at 12:34
• Take-home tests are awesome, but require a certain level of trust in the students that OP seems to be (perhaps justifiably) lacking
– cag51
Dec 12, 2019 at 18:14
• @cfr: If you are teaching somewhere where students turn in homework if it is only worth 1% then you are in a relatively privileged position. I'm not in a privileged position. I teach at a community college. What would you suggest somebody do if 90% of students won't do any homework unless it is worth at least 15-20%? This is a "when did you stop beating your wife" question. I haven't seen any evidence that there is a place where students behave like that.
– user1482
Dec 12, 2019 at 22:20

I'm not sure about your local rules, but where I'm living and teaching, the assessments should go through a pre-marking moderation review. A part of this moderation is to check the source and accuracy of assessments. The institute will lose its credit if they don't follow that. The auditor is responsible for reviewing these and can raise the alarm if he/she notices such mistakes. If the institute doesn't pass these auditions, they are not going to be accredited. What the TA is doing is not ethical, and based on the integrity rules, he (along with the unit coordinator and program/course coordinator) should be held responsible. For the students who are copying answers from those (dodgy) resources, they should acknowledge the source; otherwise, it is a case of plagiarism.