Mastering memory: Navigating the nuances of Miller’s Law
Have you ever walked into a room and forgotten why you went there in the first place? Or struggled to recall a phone number just moments after hearing it?
These common experiences highlight the limitations of our working memory, a crucial component of our cognitive function. Understanding these limitations is not just a matter of satisfying curiosity — it holds the key to enhancing how we learn, work, and make decisions in our daily lives.
Let’s look at Miller’s Law, a principle in cognitive psychology that explains the boundaries of our working memory.
Miller’s Law: unpacking the principle
George A. Miller is a famous psychologist, credited with starting the field of cognitive psychology. His seminal work in 1956 introduced the world to the concept that the average person can only hold about 7 (plus or minus 2) items in their working memory at a time, a principle now widely recognized as Miller’s Law.
This “magic number 7” has since become a cornerstone in cognitive psychology, guiding educators, business professionals, and technologists in their quest to optimise information delivery and retention.
An example:
Consider the task of grocery shopping without a list. You walk into the store, trying to remember all the items you need to buy. As you navigate through the aisles, you recall the first few items with ease — fruit, bread, milk. But, as you add more items to your mental list, like vegetables, cereal, pasta, and cheese, you start to feel overwhelmed. By the time you reach the checkout, you realize you’ve forgotten the eggs and coffee. This is Miller’s Law in action. Your working memory was saturated after 5–7 items, making it difficult to recall all 12 items without external assistance. This is why many people find it helpful to write down a shopping list or use an app, as it helps to offload some of the cognitive load from our working memory, ensuring nothing is forgotten.
The scientific roots and applications
Miller’s work was grounded in rigorous experimentation and analysis, marking a pivotal moment in the then-burgeoning field of cognitive psychology. His findings provided a numerical anchor to our understanding of memory recall, suggesting that performance in memory tasks declines when the amount of information presented exceeds the 7 ± 2 threshold.
This insight has profound implications across various domains. In education, it informs the structuring of lessons to enhance retention. In business, it guides the design of effective marketing materials. And in technology, it shapes user interfaces to reduce cognitive load. Miller’s Law underpins the strive for simplicity in design, ensuring that information is presented in digestible chunks, thereby grabbing and holding attention in an increasingly complex world.
No theory is without its critics, and Miller’s Law is no exception. Some researchers argue that it oversimplifies the complexity of working memory, calling for revisions to accommodate individual differences and the varying complexity of information types. Despite these criticisms, the essence of Miller’s Law endures, remaining a crucial tool for understanding and optimizing cognitive performance in today’s information-saturated world.
I personally believe Miller’s magical number is a useful principle for designers. I like to use the “-2” and aim for the number of 5. 5 key messages, 5 sections of a report, and so on. I like the number 5 so much, I even named my gamification company after it — PentaQuest (now sold).
How to harness Miller’s Magic Number for optimal design
Understanding the limitations of our working memory is a gateway to enhanced productivity, clearer communication, and smarter decision-making. Miller’s Law offers a useful insight into how we process information and guides how we design.
3 ways you can use Miller’s Magic Number:
Chunk your content: Break down information into smaller, manageable chunks of 5–9 items (I prefer 5–7). Whether you’re creating a presentation, designing a website, or curating a product line, ensure that each category or section contains no more than nine items. This makes the content easier to process, helping your audience or customers to retain and engage with the information presented.
Embrace white space: Avoid the temptation to fill every inch of your design with content. Instead, use white space strategically to create visual breathing room. This not only enhances the aesthetic appeal of your design but also helps to reduce cognitive overload, ensuring that the key elements stand out and capture attention.
Prioritise and simplify: Identify the most crucial information or elements in your design and make them the focal point. Simplify complex ideas using visuals or bullet points, and eliminate any unnecessary elements that do not contribute to the core message. By prioritising simplicity, you align your design with the natural capabilities of the human brain, fostering better comprehension and retention.
References:
Miller, G. A. (1956). The magical number seven, plus or minus two: Some limits on our capacity for processing information. Psychological Review, 63(2), 81–97.
Baddeley, A. D., & Hitch, G. J. (1974). Working memory. Psychology of Learning and Motivation, 8, 47–89.
Cowan, N. (2001). The magical number 4 in short-term memory: A reconsideration of mental storage capacity. Behavioral and Brain Sciences, 24(1), 87–185.
Engle, R. W., & Kane, M. J. (2004). Executive attention, working memory capacity, and a two-factor theory of cognitive control. Psychological Review, 111(1), 102–134.
Unsworth, N., & Engle, R. W. (2007). The nature of individual differences in working memory capacity: Active maintenance in primary memory and controlled search from secondary memory. Psychological Review, 114(1), 104–132.