That's the real power. We have a tendency to just go along with our assessment (especially, informal assessment) results. We think accept and move on. Choice points force you to address the issue. I have often done a quick assessment and thought, "This is more confusing than I thought," and then just moved on. I accepted. Not only that, but I hadn't planned ahead of time for how to teach the same concept in a different way. So design them in. Set a threshold. Stick with it.
Again, with Keynote/Powerpoint it's really easy.
- Me talking and showing stuff.
- Multiple choice slide.
- Quick mental math.
- Move on to the next slide or skip ahead.