From Daniel Finkelstein...
'There are three kinds of PowerPoint slides. The one that contains so much writing that you can't read it; the one that contains so little writing that it is pointless; and the one that contains just the right amount of writing – which ensures that your audience stops listening to you while they read it.'
Finkelstein, D. (2016) Notebook, The Times, 17 September, p. 23
Then there are those graphics...!