Why you should think about cognitive load as you present numbers.

This is the third article in a series on cognitive load and corporate communication.

In our first article, we explained that cognitive load is the amount of mental effort or resources required to perform a task. The human mind has limited processing power, and when a task puts that capacity under strain, successful completion of the task becomes more difficult.

That matters when you’re listening to a lecture. It matters when you’re reading a textbook. It matters when you’re watching a movie or listening to a podcast.

It also matters when you’re researching, shopping, making a donation, or accessing a service online. And this is why cognitive load is such an important concept for marketing and communication professionals to consider.

In this article we’re going to discuss cognitive load and how it relates to another vitally important element in corporate communication: presenting statistics and figures.

Why concentrate on numbers?

There’s a lot we could talk about when it comes to cognitive load, so why should we make numbers the focus?

Because, according to Nielson Norman Group:

“Numbers represent facts, which is something users typically relish.”

Research suggests that numbers make information more compelling and more credible.

But stats and figures are also important for other reasons.

In an annual report, for example, they’re mandatory. Those responsible for creating the report may hope they’re compelling, but the fact that they’re required by law and expected by stakeholders means their use isn’t even a question.

But just like words, numbers presented without careful consideration – just thrown onto a website or into a document – can be overwhelming to a reader. They can ask a lot of their mental processing facilities.

So how do you retain the numbers without risking cognitive overload in your audience?

There are a multitude of ways, but today we want to talk about just two: decomposition and chunking.

When it comes to presenting numbers, “decompose” is not a dirty word.

When you hear the word “decompose”, your mind might wander to a compost bin or some other form of biological decay. Maybe a splotchy banana.

In maths and several other fields, decompose means “break down”, but is free from any… ahem… smelly connotations. In fact, the whole point of decomposing numbers, when combined with the UX concept of chunking, is to bring about a kind of visual cleanliness.

Think of mobile phone numbers. In Australia, they’re generally 10 digits long. Longer if you include an area code.

The most basic way to present that number would be like this: 0491571804. This is what researchers describe as a monolithic piece of information, a potentially imposing parcel of data that hasn’t been split into component parts.

If you’re someone who’s never seen that number before, it’s overwhelming. And if you were asked to remember it in this form, cognitive overload would likely make the task really difficult.

That’s one of the main reasons why we typically break them down. We decompose them. After that, we present them in a form that’s easier to process. That’s called chunking.

Decomposing and chunking gives the person we’re sharing our number with a much less demanding task, as well as a familiar format (generally 4 digits, 3 digits, 3 digits) and a better opportunity to employ any mnemonic devices they might want to employ.

And it works. There’s all sorts of research to say this method makes numbers easier to process.

(As a quick aside, we do the same thing with words, breaking monolithic passages into paragraphs and marking these divisions with headings and sub-headings. One of the main reasons we do this, even though we may not be conscious of it, is to decrease cognitive load.)

Examples of decomposing and chunking.

Breaking a 10-digit number into three parts is a very simple way of decomposing and chunking information. There are so many others.

A table, for example. Or a graph.

The Guide Dogs Annual Reports.

As we mentioned in our article on cognitive load and image selection, Guide Dogs took cognitive load seriously as the organisation redesigned its annual reports.

One way they did that was by employing graphs.

What would have taken several paragraphs to explain using copy alone could be summed up in a single visual representation.

The bar chart race.

Another example is an animated visualisation. One form that’s become popular over the last five to ten years is the bar chart race, which shows how dominance within a category changes over time – often decades or centuries.

In a traditional bar chart you might see how a variable – let’s say Coca-Cola sales in a certain part of the world – changes from one year to the next. Or one decade to the next.

A bar chart race generally shows a top 10 or 20 within a category – let’s say countries with the highest Coca-Cola sales – and then animates how those sales figures increase relative to sales from other countries. It’s called a “race” because you can see countries skip ahead of other countries as their sales accelerate. Countries might suddenly burst into the chart and others might just as suddenly fall out.

It’s an engaging way to present a lot of decomposed information reasonably quickly.

The Mail Chimp Annual Report.

Charts and graphs are excellent methods for breaking up information into smaller parts, but there are so many others.

As we’ve mentioned, annual reports by their nature almost always include a lot of information; without decomposition, they can be challenging to consume. In 2020, Mail Chimp released an unconventional annual report that overcame this challenge in spectacular fashion.

A cartoon character acts as a guide through a colourful, changing landscape dotted with facts, figures, and achievements of a difficult year (the first year of the pandemic). It’s creative and compelling – in fact it won a People’s Voice Webby Award in 2021 – but it’s also a beautiful example of decomposition and chunking.

Numbers are presented throughout the virtual world within shop windows, on billboards, on bus shelters, on placards… anywhere that frames and separates them. There’s a lot to take in, but because the information is so cleverly distilled and stretched across a digital story, the mental effort required to understand it is far lower than it might otherwise have been.

There’s no such thing as a perfect statistical representation.

It’s true that all graphs – in fact all visual representations – have their limitations.

It’s been argued that pie graphs take up a lot of space while providing little information, but in the Guide Dogs example, it’s a well-chosen option.

Some experts suggest that a bar chart race is all glitz and little substance. In fairness, though, it’s rarely employed in the hope of imparting a deep understanding of a multifaceted trend or statistical shift. Instead, it’s used to give a general sense of changes in power or wealth or sales (or anything), and to do so in an entertaining manner.

As for the Mail Chimp, some might suggest there’s too much happening at once, that the colour and variety distracts from the data. It can just as easily be suggested that this is an example of decomposition and chunking done with admirable imagination and flair.

The fact is, there’s no “ideal” way to present particular data. But, in general, anything – any graph, table, diagram, or chart produced with some strategic thought – is better for cognitive load than numbers presented in a monolithic alternative.