I was recently asked by the VizThink people to devote a post to the prompt: PowerPoint: A powerful tool poorly used or a poor tool overused?, so... here goes...
I do think that PowerPoint** can be a powerful tool that is misused, but its functions and autofills can also be overused. In many ways this is not the fault of the program, but the fault of the users for relying on the program to guide their presentations and thinking. (though, perhaps some blame should go to the programmers who design it to serve that purpose)
At its heart, the program is just a slide show. Its key function is to show slides one at a time after each other. Everything else is just bells and whistles. That potential is extremely powerful, but it can be misused. The choice of what to put on those slides makes all the difference. This is a reflection of the user — and their own abilities for storytelling, narrative, etc.
When slides are used as an alternative to substantial speaking they become a hinderance: Cramming too much information on a slide. Presenting information that people will be forced to digest at the same time as trying to follow your speech. Seeing the presentation as a rigid path not allowing the free form creativity of writing on a blackboard.
From my experience, slides should be used like gestures. Co-speech gesture occurs at a rate of roughly one gesture per clause, and usually elaborates upon some aspect of speech often adding a spatial dimension to it. It isn't something separate that happens to go with speech though — it expresses an integral and complementary part of the conceptualization that also goes into verbal expression.
Another analogy more pertinent to this blog (and one I discuss in this podcast), is that slides should serve the equivalent of a "panel." The slide is the image content of a panel, while your speech is like the text. The biggest difference between the two is the temporal quality of presenting them — otherwise they serve largely the same function.
Not all use of slide shows need to be clipped and truncated as the Powerpoint Gettysburg suggests. You can still have beautiful and powerful oration using slides — but it should not depend on the slides. Rather, the slides let speech be more than just sounds. It has to be a multimodal expression, where both slides and speech work in concert with each other to achieve something more. The ability to do this, I would suspect, is cognitively the same whether it's done in print or on a screen.
PowerPoint is not a substitute for lack of narrative skills, and its problems can largely be fingered for forgetting or believing that (whether as a user or a programmer). Excel can't make you a powerful statistician. Word won't make you a good writer. Why should we expect that PowerPoint is to blame for poor presentations?
**My personal preference is actually Keynote. I'm going to treat this as just a discussion of slide show programs in general. If we're targeting PowerPoint specifically, then you can amp up my dislike of the autofills, etc.