Don't ask “Any questions?”
Asking a question during a talk is a very active process. It requires enough comfort with the presented subject to find holes in the explanations given, find the right words to describe these holes, and formulate an actual question. Once the question is formulated, asking it is another challenge. It requires confidence that the question was not answered earlier, and that the question is actually helpful. Then only, with good timing, one may ask the question. Because of this, only confident people who are attentive and comfortable with the talk tend to ask questions. Those are not the people you want feedback from.
Fortunately, when giving a talk, there are other ways to get feedback. Similar to asking questions, there are all sorts of active feedback: raising hands, clapping, leaving the room swearing, etc. However, a very overlooked type of feedback is passive feedback, i.e. when the audience does nothing. The lost audience, those who require help, those you actually want feedback from, they are particularly good at passive feedback. They get lost, freeze, and do nothing. They will thus send plenty of passive feedback, if asked for.
Usually, when opening for questions, the speaker signals a checkpoint in the talk; a moment when it is possible to go back and re-explain stuff. The problem with this is that the audience must get active (by formulating and asking questions) to actually signal their need to go backward; their need for help. Remaining passive, instead, falsly signals that the talk can go forward. Too often, the talk goes forward because the audience was passively getting lost. Even worse, since only comfortable and attentive people ask questions, their questions often push the talk further, leaving even more people behind, and giving the impression to the speaker that the talk can go faster.
To really help your lost passive audience, checkpoints and feedback should work the other way around. A passive audience should indicate that more explaining is needed. People should need to get active for the talk to go forward.
Instead of the traditional “any questions?” the speaker could ask: “raise your hand if you are following.”
The speaker could then literally count how many people are comfortable with the pace of the talk. If only few hands rise, one must go back, until people actively ask to go forward. In this way, the speaker transfers his responsibility to make an easy talk to the audience. It is now the audience who decides if things can become harder. They have to raise their hands, once in a while, to signal “I am ready to know more”.
This proposal of using passive feedback as a signal to slow down is a lot scarier for you, the speaker, than asking the audience for questions. How will you know what to clarify without a clear question? What if the audience slows you down too much? What if you can’t finish your talk because they get stuck at the third slide and never go on? What if they need way more basic notions than you prepared for! Do you even know these basic notions? You surely won’t have slides to explain them! And what about all the slides you worked on and won’t get to present? What a waste of time! Waiting for the audience to decide when to go forward really seems like a bad idea.
Obviously, asking for questions is a lot safer for the speaker. However, my point is that it is very unhelpful for the audience. You may prefer to safely reach the end of your hard worked slides, but isn’t it a far worse waste of time to show all these slides to an unreceptive audience than to get stuck midway and actually teach something? I believe good speakers are prepared to present their subjects at any level to any audience. This requires far more work than only stacking a bunch of slides together. In fact, I believe the above worries indicate that preparing slides is among the worse ways to prepare a talk, but this is a subject for another day. For now, you may simply want to try not asking “any questions?” when you give a talk… I will.