First, note that the statement in this blog’s title reflects my personal opinion. Capitalization rules for (slide) titles do exist (see e.g. capitalizemytitle.com/). I simply prefer not to use them. Here’s why…
To me, projecting an over-capitalized slide is similar to using pluralis majestatis, a.k.a. the royal we. It’s like speaking formal language rather than prose. It may (or may not) make a presenter look more important, but it will never camouflage bad content or a lack of presentation skills.
The situation becomes even worse when people start capitalizing all words in bullet points or isolated words in the middle of a plain text (unless you’re writing in German, of course). And I even don’t want to think of people who use ALL CAPS on their slides (or in their tweets) If Capitalizing Words Is Like Using The Royal We, then WRITING IN ALL CAPS IS LIKE SHOUTING AT YOUR AUDIENCE.
So please use the shift key sparsely and thoughtfully. Always be consistent in your style: don’t feed the chameleons. Vary your slide templates and avoid wordy texts or long bullet lists. As I mentioned in an earlier post on this blog, full-sentence assertions are often better than short catchy or meaningless headlines. And, remember that it’s sometimes also good to use a plain graphics slide with no header text at all.