It's an incredibly common mistake, for the presenter to put up slide after slide that is just a script of what they want to say - then your brain has to choose between listening or reading, to the detriment of both.
I have more sympathy with intro and outro summaries, as long as the bullet points are short and delivered one at a time while the speaker expands upon each one.
Slides should be a visual aid, not a substitute for presentation.
The best presentation I ever saw was done by a colleague of Mikel Harry's at a Six Sigma conference in Frankfurt. The presenter had no ready made slides but he had an overhead projector, three transparencies, a handful of dry marker pens, and an eraser. As he spoke he sketched charts and diagrams to illustrate his points. If an audience member asked a question he was able to provide an answer in both words and with another sketch.
Reminds me of Presentation Zen or the 10/20/30 rule which states that “a presentation should have ten slides, last no more than twenty minutes, and contain no font smaller than thirty points.”
I have more sympathy with intro and outro summaries, as long as the bullet points are short and delivered one at a time while the speaker expands upon each one.
Slides should be a visual aid, not a substitute for presentation.