Is it a proper etiquette to restrict questions from conference presentation only?

Question

Until now, I never engaged in presenting a conference paper. In the near future, I may likely need to give a seminar on a conference paper. In order to gain knowledge about conference presentations, I watched videos of seminars given by authors of accepted papers of previous years which are available on YouTube.

I can classify the seminars based on the type of questions asked by participants into 3 categories:

1. No questions from participants;

2. Questions solely based on the contents of the presentation;

3. Questions about research that happened a long time ago (say 20 years) that might be related to the presented paper.

The questions of category 3 are generally from domain experts. The questions are along the lines of:

The technique used by your published conference paper (say, on page no:3) seems similar to the technique that has been used in some other paper titled ______ by _____. How is your idea different from their techniques?

In some cases, if the corresponding author, who is presenting the paper, encounters such questions, other people from the audience, probably other authors, responded to the questioner since the corresponding author was not necessarily aware.

In this context, is it proper etiquette to prevent such questions by saying something like the following?

I will gladly answer any questions about the contents that are present in my presentation slides. If there are any other questions, feel free to email me.

Answer 1

I think you are starting from a wrong premise. Why would you want to restrict such questions? It is useful for you to get them. If you find out about relevant research from 20 years ago that you did not know about, you learn something new. Maybe it contains useful techniques for your next paper. Maybe it can help you focus on a different problem.

Are you afraid that you might get questions you don't know the answer to? There is nothing wrong in answering "I did not know about this paper. Could you send me a reference?". There is no shame in that. Even if it is something you should have known about, it is a learning moment, and you will know the next time. Even if you solicit questions via e-mail, maybe people will not want to take the time to send an e-mail to you, and you have lost that knowledge.

By restricting questions on your presentation, you give the impression of someone who is not interested in feedback, exchange of opinions, and learning something new. We all have things we should know but don't. Embrace it and don't be afraid. If you hide your head under the sand, you will not become a better researcher.

Answer 2

I suggest that you don't try to restrict questions in any way. Among other things it might be resented, but probably just ignored. Welcome any questions. Feel free to answer with "I've not thought about that, sorry."

But a better "answer" is to invite the questioner to discuss the issue off-line. It is an opportunity to expand both your scope and your circle of collaborators. You don't/can't know everything, but you can learn from others.

Deep questions are fine, but it is hard, even for an expert, to give a good answer with the time constraints of conference presentations.