Chunking explained: why less information leads to better decisions

Picture this. You walk into a meeting and the presenter clicks to their first slide. It contains 47 bullet points, three graphs, a table with twelve columns and a disclaimer in tiny print at the bottom. Your eyes glaze over. You feel your attention physically retreating, like a turtle pulling its head into its shell. Fifteen minutes later, you leave the meeting with absolutely no idea what was just proposed — or what you are supposed to do about it.

Now imagine a different meeting. Same topic, same data, same presenter. But this time, the story is broken into three clear parts. Each part has one central message. The data appears only where it supports that message. At the end, three concrete next steps. You walk out knowing exactly what was decided and what your role is.

The difference is not the quality of the information. It is the structure. And in behavioural science, there is a name for this structure: chunking.

What is chunking?

In 1956, cognitive psychologist George A. Miller published one of the most influential papers in psychology. Its title has become legendary: “The Magical Number Seven, Plus or Minus Two.”^[1] Miller demonstrated that our short-term memory — what we now call working memory — has a remarkably limited capacity. Most people can hold roughly seven items in mind at once. Not seventy. Not seventeen. Seven.

More recent research by Nelson Cowan has revised that number downward. The real capacity of working memory for most people is closer to four items.^[2] Four. That is the amount of mental space you have to work with at any given moment. Everything beyond those four slots either gets pushed out or blurs into noise.

But here is where it gets interesting. Miller also discovered something else: while the number of slots is fixed, the size of what fits into each slot is not. A single digit occupies one slot. But so does a word. Or a familiar phrase. Or even a whole concept, if it is one you recognise as a pattern.

Our brain is a pattern-making machine. As soon as we can discover patterns, it becomes much easier to make decisions and remember things.

That is the core insight behind chunking. You are not expanding the capacity of working memory. You are using it more efficiently by packaging more meaning into each slot. A chess grandmaster does not remember the position of each individual piece on the board. They recognise familiar configurations — patterns they have seen thousands of times — and store those as single chunks. The same board that overwhelms a beginner is, to them, four or five familiar ideas.

This is exactly what happened in a famous experiment with Susan Polgar, the first female chess grandmaster. National Geographic printed a mid-game position with 28 pieces on the side of a truck. Polgar glanced at it and recreated the position flawlessly. When they printed a random, meaningless arrangement with fewer pieces, she struggled. The number of pieces was not the issue. The presence of recognisable patterns was.

Chunking in everyday life

You already use chunking constantly, even if you have never heard the term. Think about how you remember a phone number. The sequence 0612345678 is ten separate digits — well beyond working memory capacity. But when you see it as 06-1234-5678, it becomes three groups. Three chunks. Suddenly manageable.

Or consider how you navigate a restaurant menu. Imagine a menu that simply lists sixty dishes in a single column, with no headings, no sections, no logic. You would feel overwhelmed and likely default to whatever is listed first, or simply ask the waiter for a recommendation. Now imagine the same sixty dishes organised under Starters, Mains, Desserts, and Drinks. Each section has perhaps fifteen items, but within that section, you are only comparing like with like. The total amount of information has not changed. The cognitive effort required to process it has plummeted.

This is also why the best teachers do not simply dump knowledge on their students. They organise it. They build on what students already know, connecting new information to existing patterns. The multiplication tables are a form of chunking: once you know that 7 × 8 = 56, that entire relationship is stored as a single unit, not as a series of additions.

Or take the way you read this sentence. You are not processing individual letters. You are recognising whole words — and sometimes whole phrases — as single chunks. Fluent reading is, in essence, a chunking exercise that you have practised so many times it has become automatic.

Chunking is all about presenting information in a way that makes it easier for people to process.

Let me give you a small demonstration. Try reading these three sentences once and then reciting them from memory:

Remember far is to information easier.
Pieces is divided into up it if.
Our logical are head that patterns in.

Difficult, right? Now try these:

Information is far easier to remember.
If it is divided up into pieces.
That are logical patterns in our head.

I suspect the second version was almost effortless. The information is identical. The only difference is structure — the presence of recognisable patterns. That is chunking at work.

Why chunking matters at work

If chunking is so natural and familiar, why do we keep getting it wrong in professional settings? Because the environments where we most need chunking are precisely the environments where we are most tempted to throw everything at people at once. Presentations, onboarding programmes, product interfaces, strategy documents — they are all areas where the urge to be comprehensive trumps the need to be comprehensible.

Presentations that land

A presentation that works follows a ruthlessly simple structure. Not because the topic is simple, but because the presenter has done the hard work of chunking complex information into clear, digestible sections. Three core messages. Each supported by one key piece of evidence. A single call to action. The audience does not need to see all twenty-seven data points. They need to understand the three things that matter and remember what to do next.

Compare this to the standard approach at most organisations, where the implicit assumption is: the more information I include, the more seriously I will be taken. The result is decision fatigue before anyone has reached the recommendation slide.

Onboarding that sticks

New employees are routinely subjected to what can only be described as a firehose of information. Here is the company history, the organisational chart, the IT system, the HR policy, the compliance training, the team introductions, the project overview — all in the first week. The result is predictable: almost nothing sticks.

Organisations that understand chunking design onboarding differently. They break the first 90 days into phases, each with a clear focus. Week one: meet your team and understand your immediate role. Week two to four: learn the core tools and processes. Month two: start contributing independently. Month three: take ownership. Each phase has a small number of clear objectives. New hires know what is expected at each stage — and they feel competent rather than overwhelmed.

The blogging platform Ghost demonstrated this brilliantly. Instead of overwhelming new users with the full feature set, they introduced a five-step onboarding process. Users saw a clear checklist: set up your profile, write your first post, customise your site, invite readers, enable subscriptions. Each step was one manageable action. Users who abandoned mid-process received targeted emails reminding them exactly where they left off. The result: a 370% increase in conversion efficiency.

Product design that converts

Every app, every checkout process, every subscription flow is a series of decisions. And every decision is a moment where people can get stuck, confused or simply abandon the process. Chunking is the design principle that prevents this. Instead of presenting all options simultaneously, you guide users through a sequence of manageable steps. One question per screen. One decision at a time. A progress bar showing where they are and how much is left.

This is why the best e-commerce checkouts are multi-step processes rather than single-page forms. Not because more steps are inherently better, but because each step contains a manageable number of decisions. Delivery address. Payment method. Order review. Each chunk is small enough that the user feels confident, rather than staring at a wall of empty fields.

How to apply chunking to your communication

Chunking is not just a psychological insight. It is a design tool — one you can apply deliberately every time you communicate, present or build something that requires other people to process information.

1. Start with the desired action, then work backwards. Before you chunk anything, ask: what do I want people to do after they have processed this information? That desired action determines which information is essential and which is clutter. Ruthlessly remove everything that does not serve the end goal. Then organise what remains into three to five logical groups.

2. Group by meaning, not by source. Most presentations and documents are structured around where the information came from: finance section, marketing section, operations section. But your audience does not think in departmental silos. They think in terms of questions they want answered. Structure your information around the questions your audience is actually asking, not the departments that produced the data.

3. Give each chunk a clear label. A chunk without a label is just a pile. Labels serve as anchors — they tell the brain what pattern to expect, which makes it much easier to slot new information into the right category. Think of the restaurant menu: the heading “Desserts” primes you for what follows. Without it, a chocolate fondant next to a grilled salmon is just confusing.

4. Use the power of three. There is a reason that stories, speeches and strategies so often come in threes. Three items feel balanced, complete and memorable. Two feels thin. Four feels like you could not decide what to leave out. When in doubt, chunk your message into three parts. If you genuinely have five points, consider whether two of them could be combined.

5. Make progress visible. When you guide someone through a multi-step process — whether an onboarding flow, a presentation or a project plan — show them where they are and how much is left. Progress indicators are a form of meta-chunking: they chunk the journey itself into visible stages, which reduces anxiety and increases completion rates.

Chunking and choice architecture

Chunking is one of the most practical tools within choice architecture — the discipline of designing the environment in which people make decisions. Where choice architecture asks the question, “How do we structure the options so that people can make better choices?”, chunking provides a fundamental part of the answer: by grouping options into meaningful, manageable categories.

Consider a pension fund that offers employees thirty investment options. Without chunking, this is paralysing. Research on decision fatigue consistently shows that more options lead to worse decisions — or no decision at all. But if those thirty options are grouped into three categories (conservative, balanced, growth), each containing a recommended default, the task becomes manageable. The number of options has not changed. The cognitive effort required to navigate them has.

This is also why the best digital products use progressive disclosure. Instead of presenting every feature on the first screen, they reveal functionality in layers. New users see a clean interface with a few core actions. As they gain confidence, more advanced features become available. Each layer is a chunk — small enough to master, meaningful enough to add value.

Chunking can help people make sense of the complex world they live in. And making sense of things is the first step towards better decisions.

The relationship between chunking and cognitive biases goes deeper still. When people are overwhelmed by information, they default to System 1 shortcuts — anchoring on the first number they see, choosing the familiar option, or simply avoiding the decision altogether. Chunking reduces this pressure. By making information manageable, you give people the cognitive space to engage their System 2 thinking — to actually weigh the options rather than grabbing the first one that feels safe.

Common mistakes with chunking

Chunking sounds deceptively simple. Group things together. Make it easier. What could go wrong? Quite a lot, as it turns out.

Mistake 1: Too many chunks. If you chunk a presentation into nine sections, you have not chunked anything. You have simply created nine problems instead of one. The whole point of chunking is to reduce the number of items someone needs to hold in mind. Research suggests that three to five chunks is the effective range. Beyond that, you are defeating the purpose.

Mistake 2: Chunks that are too large. A chunk is only useful if it genuinely feels like one thing. A twenty-minute presentation section that covers five subtopics is not a chunk — it is a mini-presentation hidden inside another presentation. If people need to take notes within a chunk to remember what it contained, the chunk is too big.

Mistake 3: Arbitrary grouping. Chunking only works when the groups are meaningful to the person receiving the information. Grouping items alphabetically when your audience thinks in terms of priority, or grouping by department when your audience thinks in terms of customer impact, creates structure without reducing cognitive load. Always chunk from the audience’s perspective, not your own.

Mistake 4: Forgetting the transitions. Chunks do not exist in isolation. People need to understand how chunk one connects to chunk two. Without clear transitions — a brief summary, a linking statement, a visual bridge — your beautifully chunked information feels disjointed rather than structured. Good chunking creates a sense of flow, not a series of walls.

Mistake 5: Chunking as a substitute for reduction. Sometimes the problem is not that information is poorly organised. It is that there is simply too much of it. Chunking is not an excuse to keep everything. The first question should always be: can I remove this entirely? Only after that should you ask: how do I organise what remains?

Frequently asked questions

What is chunking in behavioural science?

Chunking is the cognitive technique of grouping individual pieces of information into larger, meaningful units called chunks. Instead of processing each item separately, your brain treats a chunk as a single unit, freeing up working memory capacity. This makes information easier to remember, understand and act upon.

How many items can working memory hold at once?

George Miller’s classic 1956 research suggested 7 plus or minus 2 items. However, more recent studies by Nelson Cowan and others have revised this downward to approximately 4 items for most people. Chunking allows you to work within this limit by grouping related items into single units.

What is a practical example of chunking?

The most familiar example is phone numbers. The sequence 0612345678 is difficult to remember as ten separate digits, but chunked as 06-1234-5678 it becomes three manageable groups. The same principle applies to onboarding processes, presentations, product menus and any situation where you need people to process multiple pieces of information.

How does chunking relate to choice architecture?

Chunking is one of the most practical tools within choice architecture. By grouping options into meaningful categories, you reduce the cognitive load on the decision-maker and make it easier for them to navigate choices. Restaurant menus chunked into starters, mains and desserts are a classic example. Without that structure, the same dishes would feel overwhelming.

What is the ideal number of chunks?

Research suggests that 3 to 5 chunks is the sweet spot for most people and most contexts. Three chunks feel clear and confident. Five chunks still feel manageable. Beyond six or seven, the cognitive benefit of chunking starts to erode, and you are essentially recreating the overload you were trying to solve.

Conclusion

Chunking is not a clever trick. It is a fundamental acknowledgment of how human cognition works. Our working memory is small. Our attention is finite. The world throws more information at us than we can possibly process. The organisations, communicators and designers who understand this have an enormous advantage — not because they have better information, but because they present it in a way that the human brain can actually use.

Every presentation, every onboarding process, every product interface is an opportunity to either overload people or empower them. Chunking is the bridge between complexity and clarity. Between information and understanding. Between a user who abandons and a user who completes.

Want to learn how to apply chunking and other behavioural science techniques to your communication, strategy and design? In the Behavioural Design Fundamentals Course you learn to use the SUE Influence Framework to understand what drives your audience and design interventions that genuinely work. Rated 9.7 by 10,000+ alumni from 45 countries.

PS

At SUE our mission is to harness the superpower of behavioural psychology to help people make positive choices. Chunking teaches us something humbling: the limit is not in people’s willingness to engage with your message. The limit is in working memory. And that limit is not a flaw — it is a design constraint. The best communicators, designers and leaders do not fight it. They work with it. And in doing so, they make complexity feel simple, choices feel manageable, and action feel obvious.