Posted on behalf of Materials Girl:

Inspired by Mushy's recent post, as well as classes with presentations that put students to sleep... PowerPoint does not (necessarily) equal lecture!

Well, at least from the perspective of a professor communicating to students. Staring at slides, no matter how well-made, has never allowed material to absorb into my brain as well as the traditional ‘chalk-talk’. Technology allows for the creation of wonderful things, but even the effectiveness of the best, most beautiful slide pales in comparison to a blackboard under the spell of an eloquent, but chalky, professor.

For scientific presentations in general, audiences are not likely expected to explicitly learn the material and to be tested in the horrifyingly near future. Hence, I presume that slides are (typically) superior in those situations - especially if made following Mushy’s guidelines.