Nothing irks me more when I walk into my session room than the prior presenter still standing up there doing his thing eating into my 15 minutes of prep/setup time. Conferences have fixed length sessions for a reason. So that the audience knows how long the session will be, so that the presenter knows how much material to prepare, and so that the speaker knows how long they have before their session to get setup.
When a presenter runs over their time into the next presenters setup time this shows that the presenter didn’t have a good enough grasp of their session to set the right cadence, and they didn’t have good time management skills to know when they should have skipped some slides so that they’d finish on time.
Vendors are the worst at this at their lunch sessions. Lunch sessions at events like SQL Saturday’s typically don’t have much prep time between the lunch session and next session, so when the vendor runs over they are eating directly into the next presenters time.
Giving a session which runs short isn’t good either. As presenters we like to pad a sessions with 5-10 minutes of questions that we think are going to show up during the session. But when they don’t we need to have enough material to fill the time slot fully. After all that’s what the audience came to see. If you’ve got a 60 minute session slot, and 45 minutes of material and no questions, you’d better have some extra material to fill the extra 15 minutes with. When I was a TechEd Europe this year I wondered up to my session room very early, while the prior speaker should have still been presenting. I figured that I’d stand at the back and catch the last few minutes of his session before I got setup for mine. However when I got there his session was already done, with him standing at the front with a small group of people asking him questions. He finished easily 15 minutes early (I’m guessing).
Time management is hard. Especially when giving a presentation to a group, as you may not have a clock running to tell you how much time you have left. But there’s apps for your phone, or you can use the timer in PowerPoint (as long as you don’t close PowerPoint to do a demo), or a room monitor who can give you a signal at 5,10,15 minutes before you end, etc. There’s lots of ways to fix the problem so that the attendees get the session of the length that they are expecting while still getting the information across to them.