I submitted my master‘s thesis a few days ago. The official deadline is next Friday.

Today I spotted some serious issues in my thesis. In particular, in my main theorem and the main proposition that follows I did two critical mistakes.

To give some context, my thesis is a math thesis and in the proof of my main theorem I write that some group $F$ acts on $\Aut(G)$, which is simply a wrong statement. The correct statement was that $F$ acts on $G$. I did the exact same mistake in the main Proposition that follows thereafter.

The assertions are correct, provided the reader knows what I actually meant, but the statement, as is stands, is wrong.

It‘s so embarrassing, I feel so depressed. I spent so much time on my thesis, I read it easily 20-30 times. I don‘t know how I managed to miss these errors.

I sent an email to my supervisor, asking if it‘s possible to submit a corrected version but I think my chances are slim. I also feel so embarrassed since I wanted to pursue a PhD and I‘m seriously afraid to be considered a complete failure.

I don‘t know what to do.

Update: The university replied to my email, saying that I get the chance to resubmit a corrected version since the official deadline has yet to pass. I feel very grateful, but still incredibly ashamed that I caused so much trouble.

I also wanted to thank everyone for their encouragement and their heartfelt replies. I really appreciate every single comment and answer.

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    This depends on local rules. Only they can answer or decide. Prepare a corrected version so that you can quickly submit it possible.
    – Buffy
    Nov 26, 2023 at 15:44
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    When a correct version of the statement exists you are ok (and should be allowed to fix, or add an errata slip if the thesis is already in print). If it makes you feel better here's what happened when I submitted my PhD dissertation for the internal examiners to check. A friendly professor pointed out one proposition: From the preceding text I know where your argument is heading, and it works as intended. But look what exactly you have written as the statement of this proposition! It was embarrassingly wrong :-). Something similar happened to my first-born PhD-student. At his defence. Nov 27, 2023 at 5:40
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    So $F$ acts on $G$. Which is the same as to say that $F$ comes with a homomorphism to $\mathop{Aut}(G)$. I understand that you are annoyed by your mistake in language, but it’s not a biggie.
    – Carsten S
    Nov 27, 2023 at 11:25
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    "I read it easily 20-30 times. I don‘t know how I managed to miss these errors." Welcome to the club! We have jackets. :-)
    – Vorbis
    Nov 27, 2023 at 11:57
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    I understand your frustration but error is human. Even in published papers with peer review, there are some mistakes, typos etc. This is the reason why corrigendum exist and quite common in many fields. Nov 27, 2023 at 16:20

4 Answers 4


This is a completely minor error (a "mathematical typo", in effect), the likes of which occur every day in actual preprints that people publish online, and sometimes even in published math papers. It is basically harmless, especially if you state your theorem correctly in the intro.

An actual critical error is "the proof of one of my main results has a mistake in it and I don't know how to fix it", not "I made a typo in the statement of my theorem".

If you want to succeed in your PhD, I would advise you to abandon this idea that every piece of work you submit needs to be completely flawless or else you ought to be ashamed of yourself. This is not how other will judge you, and it should not be how you judge yourself. The idea that people you will be "considered a complete failure" based on this is simply absurd.

Do you think that other people are "complete failures" when they make a mistake like this? If so, I recommend changing that perspective before you start collaborating with others. If not, why do you imagine that they would think this about you?

  • 4
    Thank you very much for your encouraging response. To adress the question of your final paragraph: I would never think of fellow students of colleagues as failures. Quite the contrary, I always admire their work and that is why I feel so depressed about mistakes I do. I've seen some master's theses of fellow students and they were all flawless and incredibly well done.
    – Zest
    Nov 26, 2023 at 18:49
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    @Zest Right. So in effect you are saying that special rules apply to you that don't apply to other people: they are allowed to make mistakes, but you are not. Or perhaps you are imagining that other people don't ever make mistakes like this, which is plainly false. As an anecdote, I've published an actually incorrect theorem in a journal paper (a minor side assumption was missing) and I am confident that no-one thought of me as a "failure" because of this. If, as per Aristotle, excellence is a habit and not an act, then the same applies to failure: one error does not a failure make. Nov 26, 2023 at 18:58
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    I appreciate your feedback, I really do. Thank you vm.
    – Zest
    Nov 26, 2023 at 19:04
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    @Buffy Sure, I don't know what the rules of the OP's institution are, I was mainly addressing the OP's feelings of being a failure. I'm assuming the OP understands that no-one here speaks for their institution/advisor. If the goal is to give an answer that is 100% guaranteed to be correct, then indeed "only the instution/advisor can provide the answer". My goal is to try to provide useful answers ("all or almost all mathematicians I know would consider this a very minor mistake, not a critical error"), not legalistic infallible answers ("we can't say, it depends on your advisor/institution"). Nov 26, 2023 at 20:15
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    Thanks Chris. My university and my supervisor replied to my emails. They allow for submitting a corrected version before the official deadline has passed. My supervisor was very supportive and very understanding. I feel so grateful, but still sort of worried that I might have caused unnecassary trouble for others.
    – Zest
    Nov 27, 2023 at 10:01

I am not an expert in graph theory but it sounds just like an error in statement, while the proofs are actually true for $G$, instead of $\textrm{Aut}(G)$. This seems to me just like typo and not a serious mistake.

Communicating with your advisor is in the end a very wise decision. He must know the best. We do not know the guidelines of your university, department, country. The only general advice is to keep calm, act rational, and do not presume too much about the thoughts of the others.

Next time, you might consider leaving the extra days until the deadline for some light proofreading. Of course, I don't know what the procedure is like at your university and whether there is some advantage in submitting the thesis earlier. Feel free to comment.

  • 3
    Thank you very much for the encouragement. I deeply regret submitting a week earlier than necessary but I was confident that everything was correct. For some reason, these two issues were absolutely invisible to my eyes, I have no idea how that happened. In the introduction the statements are correct, I repeat both statements in the body where I slighty changed the phrasing. That is where the errors occurred. But since its twice the same error, it looks really bad.
    – Zest
    Nov 26, 2023 at 16:02
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    The problem is that this is such a obscure situation that there is no written rules about it to find in any of the official documents of my university. As I said, I sent an email to my supervisor in hopes of having a chance to resubmit, but I think this will not be allowed and it's so embarassing. It seriously affects my mental health to a point where I become severely depressed because all the hard work is just worthless if I fail so prove that I can't work without doing these careless errors.
    – Zest
    Nov 26, 2023 at 16:39
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    @Buffy You are right and while I thought I am clear about stating my personal feeling, that should not be in the answer anyway. I deleted the paragraph.
    – Jan
    Nov 26, 2023 at 21:12
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    @Zest Well, communicating with your advisor is in the end a very wise decision. He must know the best. We do not know the guidelines of your university, department, country. The only general advice is to keep calm, act rational, and do not presume too much about the thoughts of the others. (I edited my answer to reflect this.)
    – Jan
    Nov 26, 2023 at 21:14
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    @Zest: Please know that everyone who has made a similar mistake as you did all feel the same way, but in the end life is much more than academics. So please take some time off for a break. You have proven a theorem, and the people who care about it (at least you and your advisor) know that. The proof is the main achievement.
    – user21820
    Nov 27, 2023 at 3:50

I'm a practicing mathematician. If I was reviewing your thesis I would probably notice that the statement of the theorem looks surprising, I'd skim the proof and pick up that you're actually working with $G$ and not $\mathrm{Aut}(G)$, mark it as a typo, shrug and move on. If I was feeling particularly nitpicky I would ask you about it during the thesis defence, and I would expect this conversation to take around 10 seconds.

Bear in mind that, for better or worse, hardly anyone reads MSc theses. It's unlikely it will be read by anyone besides your supervisor and reviewers - to whom you can explain this was a typo. Even if you're embarrassed by this mistake (which there really is no need to be) you can be confident that it will not be widely known.

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    Thanks for your perspective Jakub.
    – Zest
    Nov 27, 2023 at 21:24

I'm glad to see this has come to a positive resolution. Everyone else has given good advice -- this isn't a huge deal, mistakes happen all the time, etc.

When we read something we've written ourselves -- and we are still deeply engrossed in it, it is very easy to read what we meant to write instead of what is written. Typos and mistakes that jump out at us later are simply invisible to us.

In my experience, changing the pace of reading can help a lot.

  1. Read the document out loud. You don't have to make anyone listen, just go someplace quiet and read it out loud. If you feel strange, read it to your dog or a tree. Read all the equations out loud. Read all the figure labels too.

  2. Get someone else to proofread it. Hopefully you have a graduate school friend who knows enough about your work to understand the nomenclature. A thorough reviewer will check your equations and derivations. It will take a lot of time. Expect to owe them a meal and/or a drink -- and be ready to return the favor when it is time to review their work.

  3. Get away from the work for at least two weeks. Leave yourself time at the end of your project before the deadline. This may be the time you work on your presentation, but hopefully you can get your mind away from the project. That way, when you return, you will have a fresh perspective.

Even with these steps, mistakes will slip through. Don't sweat them. Everyone is human.

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