Garr Reynolds said you can’t go both deep and wide in a presentation. A deep presentation explores one aspect of a topic in depth, whereas a wide presentation gives an overview of the entire topic.
I agree with Garr, but would go one step further – deep is better than wide (see also Jon Thomas’s post on deep vs wide). Here are six reasons why I recommend against giving an overview presentation:
1. It’s not memorable
In an overview presentation you can only cover each issue at a superficial level. The belief that mentioning an issue means that people will get it and remember it, is an illusion. People remember things when you have time to develop the issue, give them examples and explore the pros and cons. Making something sticky requires depth.
2. Nothing will stand out
When you give an overview presentation not only do you cover each issue lightly, you cover a lot of issues. That means that no one issue will stand out and your audience is likely to remember less, not more. Presentations are not a good vehicle for transferring a lot of information from one person to another. Check out this post for more reasons why you should avoid information overload: How to stop information overload in your presentation.
Both these points are supported by educational research that shows that students learn better when material is covered in depth. A study of over 8,000 college science students found that those who had studied at least one major topic in depth at high school, got better grades in college science. When Robert Frank, a professor of economics, reduced his coverage and concentrated on teaching core economic principles in depth, his students did better. Teacher websites encourage teachers to teach depth even at the expense of covering the curriculum.
3. Positions you as a generalist
Anyone can give an overview of a topic. Only an expert can deliver an in-depth exploration.
4. It’s uninspiring
An overview is rarely inspiring or motivating. An in-depth exploration of a particular aspect of a topic is more likely to inspire people to find out more about the topic.
5. It’s boring
If there’s a mix of knowledge levels in your audience, you’ll bore anyone who’s beyond beginner status and possibly beginners too. Covering material at a surface level is rarely engaging. You want your audience to be in a state of “flow”. That happens when your material is not too easy and not too hard. For more on flow, and how to achieve it see: 7 ways to keep audience attention during your presentation.
6. It’s not efficient
Why bother with the expense and effort of a presentation to give people an overview of a topic? They can get the information much more efficiently in other ways, via a report, your organization’s intranet, a short elearning module, or surfing the internet.
There may be situations where an overview presentation is required. But before you give such a presentation make sure there’s no alternative way of delivering the information. Presentations are much more suited to covering one issue in-depth. A deep presentation is more engaging, inspiring and memorable.