As well as asking people to write big words on their slides we encourage them to write in 'whole thoughts' - sentences or headlines rather than chapter headings.
Let's imagine you're discussing the issue of 'X' in your organisation. You will quite often see a slide with a heading like this:
They use the slide to introduce the subject and then discuss it in front of you.
This fits the criteria of being big and might qualify as being simple but it's not clear. And news people would describe it as burying the lede.
It's quite easy to get to the end of that discussion without knowing exactly where they stand on the subject of X. People immersed in their specialism often forget to state their assumptions.
We would encourage, instead, writing a slide like this:
And then discussing the reasons, or enumerating them on subsequent slides.
This approach has a few advantages:
1. It forces you to say what you actually think
And means you can't get away with the common presentation trait of just listing all the things you know, without actually stating what you think should be done.
And, especially usefully in large organisations, it means you'll probably need to agree this with your colleagues before you say it to anyone else. Writing and agreeing presentations like this takes longer than the vaguer stuff but it's a way of making sure the organisation knows what it thinks and what it's saying - it's a tool for organisational thought.
2. It encourages everyone else to concentrate on the main thing
It's hard to leave a slide like this without either agreeing, disagreeing or fairly explicitly dodging the question. You certainly can't say you haven't been told. It discourages discursive rambling around the topic, though that still turns out to be possible. At the least, it tends to funnel the rambling towards agreement or otherwise.
3. It works on social media
Increasingly, when doing a public presentation, the most interesting and coherent slides end up on instagram or twitter. If nothing else it's a good discipline to think of your slides in these terms. Do they communicate on instagram, without you droning on in front of them?