How much information is too much?

Puppy tilts head and looks confusedMuch of what we write often sails way over our readers’ heads.

The problem is that we take our own knowledge for granted and assume that everyone else knows it too. As I explained recently, we all know more than we think.

Even if you’re new to a topic yourself, it’s still surprisingly easy to whizz past your audience’s level of expertise during your research.

But there is another factor that can lead us to overload our readers’ brains, which is that we all have a finite capacity for how many new points we can handle at once.

Magic numbers

You may already have been told that the magic number is seven, give or take a couple. If so, forget that (pun intended), because the real limit is much lower.

In fact, research shows that the human brain struggles to handle more than just three to five new pieces of information at a time.

To see what I mean, try this quick thought experiment.

Vanishing words

Imagine you’re learning a new language, and today you want to memorise ten new words.

You read the first one, repeat it to yourself and try to commit it to memory. Then you do the same for the next three words on the list.

But by the time you get to the fifth word, the first word seems to have mysteriously vanished from your mind. So you go back to the top of the list to remind yourself, only to find that you’ve now forgotten another one instead.

Sound familiar? This happens because we initially hold new information in our working memory, which is easily overloaded.

It’s not such a big issue if we can relate the information to something we already know (in our example, that might be other words that sound or look similar). But if we don’t, we quickly lose the thread.

Still motivated

I had this experience myself only this weekend, while watching a video tutorial on playing guitar. I started well but soon found myself struggling as the instructor tried to build on the three or four new concepts that he’d already introduced.

This happened even though I found the video itself interesting and was very motivated to learn. It still felt like my brain was full just a few minutes in, for the simple reason that it literally was.


Soon lost

Or at least, my working memory was – the part that I needed most at the time.

This is exactly what will happen to your reader if you try to include too many new concepts in a document. They’ll follow along up to a point, but then they’ll become confused and soon feel totally lost.

The trouble is, you won’t know you’ve done it. Because, unlike the reader, you can relate the new information to specialist knowledge.

You built your report or proposal on expertise that you have and your reader doesn’t.

Hack the brain’s limits

There is a way around this problem, which is to group the new concepts into three to five chunks.

Here’s an example of how it works. First, try memorising these ten letters:


Now notice how it’s easier if I group them together:




That’s because your working memory now only has to hold three pieces of information. But it’s even better if I split them into chunks that you probably recognise:




The key to chunking information is to attach it to what’s already familiar to the reader.

What’s familiar?

So, before you introduce new information, ask yourself what the reader already knows. Then try to group and tie new information to that.

With a proposal, this could be the various parts of a problem that a decision maker has already told you they’re trying to solve. Focus on each of these in turn.

With a report, list the things that the reader is most concerned about or interested in. Then divide the information into chunks that match the list.


More help

I explain more about how to structure documents here.

Or you can check out Gary Woodward’s article, What your boss doesn’t want from your report.

Finally, the memory psychologist Nelson Cowan explains why the magic number is four, not seven, in this paper.


Image credit: Chris Arthur-Collins / Unsplash

The definitive guide to transforming the writing of individuals and teams