The use of humour in presentations is, ironically, a common source of fear and loathing. This is mainly because people confuse humour with telling jokes. From experience, jokes told during presentations are usually not very funny at all and cause more of a collective groan than laughter. Also, the use of humour is often seen as unprofessional, especially in more business-oriented surroundings. But humour, laughter, and an element of play are natural parts of being human, so why should they be banned from presentations?
Simply said: Don't tell jokes. A joke is, by definition, a stand-alone story with a humorous end. As such, it will stand out from the rest of your presentation, so it better has some relevance to your topic or it will really stand out (in a negative way). This, however, is really hard. Also, the audience is expected to laugh at the end of the joke. What if nobody's laughing? Delivering funny lines is hard (ask any stand-up comedian). Let's be honest: most of us - especially us geeks - just don't have that talent. That shouldn't stop you from using humour in your presentation, though. But there are other, better ways to incorporate some humour that don't feel forced like jokes often do. The humour should be a natural part of the presentation.
Telling a story from your experience can offer an opportunity to include some humour. Have you ever been in a situation that's relevant to your topic that turned out to be funny? Or maybe even a bit embarrassing for yourself? Self-deprecating humour can help make the audience feel less intimidated, so it especially helps for "big" complicated topics.
If you can't think of anything, don't worry. Again, humour should be a natural part of the presentation - if there's nothing funny about your topic, don't try to force humour on to it.
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