"When we hear a great talk, we recognize how we may be able to use the conclusions (and whether we want to), integrating them into how we think about, well, everything pertaining to the subject at hand. The same conclusions, offered during a bad or mediocre version of the talk, may well lose this potential (unless the listener works very hard to ignore the distractions of the presentation to reach the conclusions from the data alone). When we leave a really great seminar, we can understand and communicate those conclusions."
https://journals.biologists.com/jcs/article/136/7/jcs261147/306217/We-need-to-talk
@halama_immuno I think nothing beats paying close attention to your audience. If you've lost them, if they're confused, you're usually able to notice and adapt. The Tridentine Mass approach, constantly with your back to the congregation, facing the slides, is a terrible approach.
@cyrilpedia Absolutely...a slide show for an "obscure" audience will produce...well, obscurity.