If I am the TA for a class, what should I do if a student asks me a question which I can't answer? While "tell the truth and say you don't know" is one approach, are there other options?


6 Answers 6


I agree that honesty is the best policy, and it's too bad if you're in a situation in which you feel worried about admitting you don't know the answer. You shouldn't try to bluff, by pretending you know but don't have time to explain or by giving an intentionally vague answer. However, there are ways of handling it more smoothly than just saying "I don't know" and leaving it at that. Depending on the circumstances, you can say "That's a really interesting question. I haven't thought about it, so I'll have to look into it, but let's talk about it in office hours." (Or you can promise to return to the topic in the next class meeting if it's really relevant to the course and everyone in the class will want to know the answer.) Or "These issues can be complicated. I don't know the details off the top of my head, but the place I'd look them up is Reference Work X. I'd be happy to show you where to find it after class." Or "That's a good question, but it's somewhat beyond the scope of this class. I'd be happy to investigate it with you outside of class."

The key is to respect the student's desire to learn. If you avoid the question or give an answer you know is inadequate, then you're being deliberately unhelpful. If you just give up and admit defeat, then at least you're being honest, but the student still isn't finding out what he/she wanted to know. If you respond by pointing the student on the road to an answer, even if you can't supply it off the top of your head, then you've done everything that can be expected of you.

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    And, even if you suspect that the student might be just hassling you, nevertheless treat every question as genuine and sincere, and respond as sketched by AnonymousMathematician. That is, the conscientious (and "innocent") response is also the best defense against suspected hecklers. Aug 20, 2014 at 19:10
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    +1. In some cases, "I don't know, but let's find out!" may also be an option. Of course, you should only try that if you're confident that you can work out the answer reasonably quickly; spending too much time working on a single question not only cuts into your available time, but can also easily bore the students. Aug 20, 2014 at 21:42
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    @IlmariKaronen I have done that and sometimes was not able to find the answer. No biggie -- just abort after 5/10/... minutes, say "This seems to be harder than I though, I'll get back to you! But now we need to continue with the other material" and all is good. I think that students can learn more from watching how you approach a problem you don't know already know the answer to than they can from watching you present a polished solution.
    – Raphael
    Aug 21, 2014 at 6:08
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    +1. Or - gasp! - you might even ask whether some other student has an idea (assuming that this happens in a classroom setting)! Aug 21, 2014 at 11:18
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    @math137: If you are repeatedly unable to answer elementary questions, then yes, the students would (and should) become alarmed. On the other hand, the solution to that problem is to learn more, not to try to hide your ignorance from the students. But it's easy for students to ask arbitrarily obscure or difficult questions, and curious students will sometimes do so; there's no shame in not having an immediate answer. Naive students may believe their instructor should know everything, but it's valuable for them to learn what sorts of things an expert does or doesn't know offhand. Aug 22, 2014 at 18:35

I'm a professor, so I am expected to know the answers, but sometimes I don't. This often involves some minor detail in a programming language.

So I usually say, "That's a good question. I don't want to give a wrong answer, so let me think about that and get back to you." We use a course management system which includes a discussion board, so I will usually then add, "I don't want to forget, so post that on the forum. That way everyone will see the answer." Then in the posted answer I try to explain how I found the information. I find this works well.


It's happening a lot so in this situation I prefer to not saying I don't know the answer" but I will say good question and let us think about it and we will discuss later

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    And the students will know right in that moment that you doesn't know the answer. I never respected any teacher who couldn't admit that he doesn't know/remember something.
    – user64845
    Nov 27, 2016 at 0:25
  • Agreed. I have never really liked professors who tried to be infallible..... Nov 27, 2016 at 7:07

I don't know the answer to your question at the moment, let us all try to find a solution together.

In that way, you are communicating the fact that there are always new ways to look at things and presented for the first time, it is difficult to answer.

Then, you might well be in the same shoes as the questioner and other students and one logical way is to sit and solve it together. You could invite the whole class if you wish; a cooperative effort. The main idea is to try to find a way to tackle the problem before it dies away.


You should say that you don't know the answer or did not prepare for answering it (especially if it is a question that is out of topic). Then you can either search for the answer with the student if you have time and it is appropriate. Or if you cannot at that moment, you can say that you will look for it and give the student some explanation by e-mail or next time. This is something that happens even to professors sometimes.

  • An alternative is to ask whether any of the students want to answer it. Or even whether they would be willing to research it and provide an answer in the next class. You needn't assume that all of the answers need to come from you. Students need to learn, not to "be told".
    – Buffy
    Jan 14, 2021 at 16:46

If that is course related Just tell them "we will get there", don't hurry. Go home find out the answer and give them answer the next day or so. :)

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    That is an attempt to fool the students. They are not stupid, and will probably see through it (specially if you do this often). I thin there is more value in teaching that it is OK not to know everything, but give the tools to figure out, as Anonymous Mathematician wrote in his answer.
    – Davidmh
    Aug 24, 2015 at 9:07
  • Best action is to say I do not know the answer. Then research it. That's it.
    – stephanmg
    Jan 14, 2021 at 16:07

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