This is a very interesting post about the Glance Test:

“…slides should be processed in 3 seconds or less. It’s impossible for people to process your slides and your words simultaneously. The test gives you a quantifiable way to test a slide’s viability as a glance medium by calculating a signal-to-noise ratio for individual slides.”

This can be a very useful tool for both teachers and students to keep in mind when developing any kind of presentation slides. I’m adding it to The Best Sources Of Advice For Making Good Presentations.