It’s called the Assertion-Evidence Format and it was developed by Professor Michael Alley (I’ve mentioned it previously but somehow never devoted a whole post to it).

First let’s look at the Assertion part of the format.

The assertion

An assertion is a complete sentence which expresses the point you’re making with the slide. It’s different from a topic heading eg: “Microfinance”. Topic headings throw away the opportunity to emphasize your point. An assertion makes a point eg: “Microfinance is about lending money to poor people”.

The benefits of assertions on slides

1. Having your main points displayed gives them emphasis. Be careful – this only applies when just a few points are displayed. If you emphasize everything, you emphasize nothing.

2. It gives the point longevity. It gives your audience more time to take it in and process it. If they were momentarily not paying attention – a quick glance at the slides and they’ve got the gist of what you’re talking about.

How to write an assertion

1. Look at your bullet-point slide and work out the single point you are trying to make with the slide. For instance with the slide below the assertion could be “Microfinance is about lending money to poor people”:


Write your assertion as a complete sentence.

2. The assertion should be short, but not so short that it’s cryptic. It’s more important for the assertion to say something meaningful, than to be short.

3. The assertion should not be a question – a question doesn’t leverage the power of displaying your point on the slide. The assertion should be the answer to the question.

Where to put the assertion on the slide

The default position for an assertion is across the top of the slide. If you put the assertion at the bottom of the slide there’s a risk that some members of the audience won’t be able to see it because other people’s heads are in the way. If you put it to one side of the slide, you’re likely to need several line breaks which makes it harder to read.

This is not a cast- in- concrete rule and will depend on the ‘shape’ of the visual content that you add.

The evidence

Now that you have the assertion worked out, the next step is to add visual evidence. Expressing an idea visually as well as verbally makes it more likely that the audience will understand it and remember it. From John Medina’s book BrainRules come the following figures:

Here are five types of visual evidence. They’re inspired by Dan Roam’s book:

1. Who/what? Photos or sketches

Photos are great for impact and evoking emotion. They can be illustrations of the real thing or a metaphor for what you’re talking about. If you have a hard time trying to think of a metaphor simply type the concept you want to illustrate into the search engine of a stock photo website (eg: istockphoto) and it will serve up lots of ideas.

If you’re telling a story to make your point, then the image can relate to that story. It will help the audience make the link between your point and the story.

Don’t use irrelevent photos for the sake of adding visual interest. It’s better to have no visual than a confusing visual.

2. Where? Maps and spatial diagrams

Only a few presentations will need a map to show where things are, but spatial diagrams take the idea a step further. When you create a spatial diagram you decide on the coordinates (the equivalent of North, South, East, West) and then place things in the “space” you’ve created. Spatial diagrams make abstract concepts more concrete as in this matrix diagram:


There’s also a lovely example of a matrix diagram on Dan Roam’s blog.

3. How much? Charts and graphs

My recommendation is not to import these directly from Excel into PowerPoint. Create your chart in PowerPoint and only include the numbers which are required to make your point. And then explain the meaning of the data.

It’s very tempting when you’ve got a whole lot of data to include all of it, but this only obscures the point you’re making (and if there’s no point to it – don’t include it). Check out this excellent post from Seth Godin for an example of this.

4. When? Timelines

Timelines can be a useful way of showing what needs to happen next and the order in which things need to happen. However, I would caution against using timelines of the past unless your topic is historical. It might encourage you to talk too much about the ‘background’ to the detriment of the present and the future – which is of far more interest to your audience.

5. How? Flowcharts

Flowcharts are excellent for illustrating a process. This is the most appropriate type of visual to illustrate my microfinance assertion:


More resources

For more information on the development of the Assertion-Evidence format see Michael Alley’s website:

Rethinking the design of presentation slides

Ellen Finkelstein has written about this format. She calls it the Tell ‘n’ Show slide design.

And Dave Paradi often uses this format in his short videos of slide makeovers.

The Assertion-Evidence format is just one way to makeover bullet-point slides. For other styles see my post The Top 7 PowerPoint slide designs.

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