One idea per slide: how to cut a deck in half

Cutting a deck in half rarely means removing half the content.

It means removing half the clutter. The ideas stay. The noise goes.

Often the slide count goes up while the weight goes down. That’s the strange arithmetic of one idea per slide.

What counts as an idea

An idea is something you could say in one sentence. It makes a claim.

“Students learn more when they explain things aloud.” That’s an idea.

“Learning methods” is a heading. It points at a space where ideas might live.

Most crowded slides are headings with lists underneath. Each item on the list is a half-formed idea. Each one deserves a slide of its own, or deserves to go.

Step 1: Print the deck, or view it small

Look at every slide at once. A grid view works. So does a printed page of thumbnails.

From a distance, the dense slides stand out. They look grey. Mark them.

Step 2: Write each slide’s sentence

Go through the deck slowly. For each slide, write one sentence underneath: what it means.

Some slides will be easy.

Others will need two sentences, or three, or you’ll find you can’t say what the slide is for at all.

That’s the information you need.

Step 3: Sort the slides into three piles

Clear. One sentence, one idea. Keep it.

Crowded. Several ideas in one place. Split it.

Unclear. You can’t say what it means. Cut it, or rethink it.

Be honest with the third pile. If you, the speaker, can’t name a slide’s idea, the audience won’t find it either.

Step 4: Split the crowded slides

Take a crowded slide. Say it has four bullet points.

Ask of each point: is this an idea I need?

Some will be. They become their own slides, each with a single line of text, an image or a number. If you’re unsure how to lay one out, this guide on how to format an idea on a slide takes it step by step.

Some won’t. They were there because they were true, not because they mattered. Move them to your notes, or let them go.

For example, a teacher’s slide titled “Benefits of group work” with five bullets might become two slides:

• “Explaining an idea to a peer is how you find out you understand it.”
• “Groups catch mistakes that individuals miss.”

The other three bullets were supporting detail. They move to the speaker notes, where they help without crowding.

Step 5: Remove what repeats

Read the sentences you wrote in Step 2, in order.

You’ll find repeats. The same idea, said twice in different words. An introduction slide that the next slide makes redundant. A summary that summarises nothing new.

Keep the strongest version of each idea. Cut the rest.

This is usually where the real reduction happens.

Step 6: Check the flow

Read your sentences aloud as a paragraph. One after another.

Does it make sense as a story? Does each idea lead to the next?

If there’s a jump, you may need a small bridging slide. If two ideas sit awkwardly together, swap their order.

The list of sentences is now your talk, in outline. The slides follow from it.

Step 7: Design each slide lightly

Now give each idea its slide.

• One short line of text, set large.
• Or one image that holds the idea.
• Or one number, with a few words of context.

Rarely more than one of these. Never all three.

Leave generous space. The idea should be the only thing to look at. When the idea is a line of text, a set of simple headline slides is an easy starting point.

What happens to the detail

People worry that cutting slides means losing substance.

It doesn’t. The substance moves.

• To your voice. You’ll explain the examples and context out loud.
• To your notes. Facts and figures you want to remember.
• To a handout or follow-up document. Anything people need to study later.

A slide was never the right place for a paragraph. Letting it go is a relief for everyone. There’s more on this in speaker notes that let your slides stay simple.

Signs you’ve cut enough

• Each slide can be understood in a few seconds.
• You can describe every slide in one sentence.
• You don’t need to read the slides to present them.
• Flicking through the deck quickly, you can follow the shape of the talk.

Signs you’ve cut too much

It’s possible to go too far.

• A slide with a single word that only makes sense if you explain it at length.
• A jump in logic where a bridging idea used to be.
• An audience that needs a key fact to follow along, and doesn’t have it on screen.

If a number or a name is essential for understanding, it belongs on the slide. Minimal means nothing extra. It doesn’t mean nothing helpful.

A shorter talk, too

Here’s a quiet benefit. When each slide holds one idea, you notice the ideas you don’t need.

Talks often get shorter as well as clearer. Ten minutes of material that used to take twenty.

If you’re wondering what the new slide count should be, see how many slides for a talk with one idea per slide. And if you’d like a tool that starts from one idea per slide, that’s how ZenDeck is shaped.