As a result of several conference general sessions I've experienced the past few weeks I've formulated a few rules that will certainly inform my keynote speaking in the future, as well as the suggestions I offer others about effective general session and workshop design.
The longer the session, the less lecture it should include.
Unless the speaker is a masterful storyteller and is only weaving a few highly relevant yarns, there are very few people who can command an audience's full attention for more than 20-30 minutes. And even if they can command it longer because they are amazing lecturers, they just shouldn't do it.
Engage us. Please! Instead of asking rhetorical questions, what if speakers asked real questions that real people (i.e., conference attendees) actually answered? What if instead of just talking at us, speakers more intentionally spoke with us? Or let us speak with each other?
The longer the presentation (lecture or otherwise), the greater the clarity of content it needs to contain.
Speakers sometimes forget that their familiarity with what they are talking about (and the frequency they address the topic) allows them to speak at a pace far greater than what a participant's mind can absorb. When the primary teaching technique is lecture, less content actually is more. A few kernels highlighted and then expanded through examples and stories will leave participants with more learning than will a seemingly random laundry list of thoughts and observations ... unless those random insights are woven together for a few memorable threads of thinking. It doesn't have to be the ol' high school essay formula of tell them what you're going to tell them, tell them, and then tell them what you told them. But the content does need to be crafted with some crescendos that stick in participants' minds.
The greater the amount of content, the more time that needs to be allocated for participant reflections and connections.
Helping participants make connections from the content being explored to their own environments and challenges is what every speaker seeks to do. But using the name of the sponsoring organization and dropping in the name of the participants' industry or profession is no substitute for intentionally engaging participants in explorations of scenarios drawn from their own experiences.
If speakers who are your content experts aren't gifted in this aspect of the learning exzperience, it is incumbent upon reps from the sponsoring organization to supplement what the speaker can do with what is needed for participants to have a more powerful learning experience.