I will have my master thesis defense in one week and today my advisor wrote me he is not sure about a method I used to obtain a result (this will not ruin the entire work, but still will make some results useless).

I explained him the theory behind the method (which I found in a highly reccomended book, and I decided to apply after having written to the book's author to ask clarifications), but still he keeps raising doubts about it.

The fact is that now it is too late to change things, because the thesis has already been registered and anyway I do not understand why the method should be wrong. Therefore I stick to what is written in the book and to the explanation the author gave me.

I thought that maybe he just want to make sure I will be prepared to defend my work that day, but he is actually having words on the method itself, which is not something I have invented: I am just applying it as it was explained.

This is making me really anxious, because I do not know how to deal with this if such a question should be asked during the defense. I mean, I will give the same explanation, but what if someone insist on it?

  • If you have cited the work you based you method on in your thesis and believe it makes logical sense then you should be solid in defending it. Have you asked your advisor what he thinks you should do? Also have you thought about the method enough to justify your version?
    – Stephanie
    Apr 22, 2015 at 15:39
  • Yes, I thought about the method and also I checked all the equations involved retrieving them starting from the beginning to be sure there were not mistakes in the formulation. Still he doubts about the approach (I have to say also that the case in which I applied the method is really similar to the one explained in the book and this was done on purpose to check everything was done properly)
    – Rhei
    Apr 22, 2015 at 15:45
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    I think you should ask you supervisor specifically about what he thinks you should do when you're defending it.
    – Stephanie
    Apr 22, 2015 at 15:59
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    What's the name of the method, out of curiosity?
    – rschwieb
    Apr 23, 2015 at 9:56
  • The method has not a proper name. It actually consists of applying the Macaulay's method to compute a theoretical value of the stiffness of an experimental beam. It is explained here (ts.gylyxx.com/book/book80/2009875575603.pdf) starting at the end of page 342 to the next page
    – Rhei
    Apr 23, 2015 at 11:38

3 Answers 3


The part where you say that you do not understand why the is wrong and you are just stick to what is written in the book and the author's explanation is most likely to be the problem. The first step is to understand the advisor's objection to the method. Now that you know that there is a reason to doubt the method, you should concentrate critically on that method, and do your best to find the flaws in the method. Do not be distracted by the fact that it is too late to change anything, and focus on truth. It may well be that there is some minor change in the method that would solve the problem, which you need to discover. That is the purpose of graduate education.

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    Your position seems to be that you "don;t understand why the method should be wrong", and your basic reason is proof by authority - "I stick to what is written in the book and to the explanation the author gave me. it is not something I have invented: I am just applying it as it was explained". On the other hand, your supervisor (and your examiners) want to know why it should be right, and/or why it is relevant to your research. That's the basic difference between "taking a course and getting a good grade by doing what somebody tells you " and "doing research".
    – alephzero
    Apr 22, 2015 at 21:19
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    @alephzero, I find your comment pretty condescending. OP says they have worked the mathematics through and demonstrated them correct to their own satisfaction. If the advisor isn't convinced, then they need to help OP show that the proof is wrong. If the advisor doesn't understand the proof, but the result goes against his intuition, well that may just be his problem. Until he comes up with a counterexample or other form of mathematical refutation, OP is free to stand on "the result in proved in the cited reference".
    – Bill Barth
    Apr 22, 2015 at 23:27
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    I'm wasn't necessarily referring to mistakes in book's formulation of the method. I had $100 for every time I have seen a technically correct method used when it was not applicable (for example in statistical analysis of data) I would be a significantly richer person. We don't know what the supervisor's "doubts" are concerning this. Reading between the lines, I would guess the OP doesn't fully understand what the supervisor's "doubt" is either, and you can't fix a problem until you know what the problem is.
    – alephzero
    Apr 23, 2015 at 0:49
  • @alephzero: I am absolutely sure the method is applicable in my case since it is a replication of the example showed in the book made exactly with the aim of testing the whole procedure (of which the accused method is a part)
    – Rhei
    Apr 23, 2015 at 6:22
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    @Rhei: If that's how you're sure it's both correct and applicable, then that's your thesis defence. Apr 23, 2015 at 10:31

This is not something you should get to your defense with your advisor still doubting. You and he need to sit down ASAP, work through the material, and not stop until he is satisfied. I would would hope that he would be willing to take this very seriously. No advisor should let a thesis go to a public defense with this kind of question looming in their mind. No one should be forced to do a defense that their advisor thinks they're not ready for.

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    +1 Your advisor's job at this phase is to help guide and prepare you for academic success. You're not ready to defend if you can't satisfy your advisor's questions. Trying to defend without the full support of your advisor is a recipe for disaster. I strongly recommend that you do not attempt to defend until you have his full support. Postpone if you need to -- you won't be the first or the last -- because your #1 goal is to graduate.
    – Jesuisme
    Apr 22, 2015 at 20:55
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    If I withdraw I will have to postpone my defense until July and I actually don't want to waste all this time trying to figure out what his problem with this method is. Also because I presented him this part of the work nearly 2 months ago and he did not complain about it at that time (probably because he actually never looked at my results)
    – Rhei
    Apr 23, 2015 at 6:28

Criticism about other scientists methodology is an essential part of any scientific discourse. You should not consider results bullet proof anyways, that have not been verified by other research units, possibly using a different methodology.

You are lucky as your advisor told you about his objections before the defense. Make sure that you understand the reason and the consequences of the criticism, so that you can prepare a response in beforehand.

Your response should make clear that you are aware of the issue and how it would influence (or even invalidate?) the results you've obtained (if it were true). Also think about whether you think the criticism is relevant, justified and what measures could be taken to avoid the issue (as part of future works on the topic).

You might also want to add a note on this to the discussion part of your thesis and a slide about it to your presentation that you may turn to when the question comes up.

If you find out that the approach you've taken is indeed flawed it shouldn't mean that your thesis failed altogether. But you should describe specifically why and how your approach did fail and how you think future works should approach the research question to be effective. Note that there's even a bunch of journals that also publish negative research outcomes to counteract publication bias.

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