A consequence of Zen practice is increased attentiveness, a calmness and a good ability to focus on the here and now. However, for your average audience member, it is a safe bet that he is not completely "calm" or completely present in the "here and now" but is instead processing many emotional opinions and juggling several issues at the moment — both professional and personal — while doing his best to listen to you. We all struggle with this. It is virtually impossible, then, for our audience to concentrate completely on what we are saying, even for shorter presentations. Many studies, for example, show that concentration really takes a hit after 15-20 minutes. So, yes length matters a great deal.
Every case is different, of course, but generally, shorter is better. But why then do so many presenters go past their allotted time, or milk a presentation to stretch it out to the allotted time even when it seems that the points have pretty much been made? This is probably a result of much of our education. I can still hear my college philosophy professor saying before the 2-hour in-class written exam: "Remember, more is better." As students, we grow up in an atmosphere that perpetuates the idea that a 20-page paper will likely get a higher grade than a 10-page paper, and a one-hour presentation with 100 PowerPoint slides filled with 12pt lines of text will get a better grade than a 30 minute presentation with 50 highly visual slides. This "old school" thinking does not take into account the creativity, intellect, and forethought that it takes to achieve a clarity of ideas. We take this "more is better" thinking with us into our professional lives.
I gave a presentation at the Westin Hotel earlier this week for ACCJ in Tokyo. In that presentation I spoke briefly on the issue of presentation length and human attention span. Below I include a few of the slides so you can see how I introduced the topic. The idea of referring to Abraham Lincoln's Gettysburg Address to underscore the power of a short, concise speech came from Why Business People Speak Like Idiots, though the example has been used many time before.
To get the audience involved, I ask what happened on this date. Many knew the answer.
Then the next visual comes in as I say something like "Yes, that's right, Abraham Lincoln's famous speech...." Then I ask people how long it was. Some know the answer, but many would assume it was perhaps a 20-30 minute speech or longer. They are surprised to find that it was a very short speech: 2 minutes and 270 words.
Edward Everett's speech, which preceded Lincoln's and had great content, was long: 2 hours and 13,500 words. Almost a century and a half later, which speech do many still talk about? A simple example to underscore the fact that shorter is very often better.