Sometimes I am in a conference presentation or seminar which there are only a handful of audiences, and after the presentation the atmosphere simply urges the audiences to ask questions or the presenter will be embarrassed. I do want to contribute to a meaningful discussion, but the problem is that I am unfamiliar with the topic, and after listening to the presentation, I can only understand the background briefly. I cannot formulate a good question after the presentation.
You may wonder why I attend a presentation which the topic I am unfamiliar with, and sometimes it is driven by curiosity, and sometimes it is compulsory (like invited speakers from my supervisor etc). I know it may be possible to formulate a good question by reading the publication of the speaker beforehand, I have tried it actually but the efforts to understand an unfamiliar topic seems too much, and it may not worth it especially I cannot come up with a good question afterwards.
I don't want to be looking stupid after a presentation, but also don't want to start a discussion which is not quite meaningful just because nobody raises a question. Is there any way to help one to start a good discussion for a topic which I am unfamiliar with after a presentation?