If you refer to a word or phrase you mentioned earlier in your presentation, in the lingo of the
art of public speaking, that's called a 'callback.'
A Callback works well if the previous piece of material got a good laugh, or if it was a groaner.
If the previous material was good, mentioning it again will get more laughter and will make you
look polished for being able to tie the previous material to the present material, all of this is within
the art of public speaking.
If the previous material was poor, the callback will show your willingness to tease yourself,
which is an admirable quality the audience appreciates. A true professional in the
art of public speaking knows when he does well and when not; he laughs at and learns from his
Here's how it works: Let's say you used a successful two-liner in your presentation 'Don't rely on
health books too much. You could die of a misprint'. Later in your presentation someone might notice
a misspelling in one of your handouts or visuals. As a pro in the art of public speaking, you could then 'call back' and say, 'See, that's one of those misprints I was telling you about earlier.'
Another thing that might happen, that is just as good, is that one or more of the audience members
might make the connection and do the callback for you. One of them may blurt out something about your health book line. That's great if they do. You are getting them involved and allowing them to feel superior to you, which makes them the stars. Participation is part of audience attention which is the goal of the
art of public speaking.
You could then comeback to the callback with, "See, I put that there to test you." When you really get
confident in the art of public speaking, you might actually make the misprint on purpose to set up this whole scenario.