Miller's Law
Design Principles
People can hold about seven things in working memory at once.
In practice
Miller's 1956 paper put the capacity of short-term memory at seven items, plus or minus two — a figure often over-applied, but the underlying point stands: working memory is small, and interfaces that ask people to hold many things in their heads fail. It is why phone numbers are chunked, why long forms are stepped, and why a good interface shows you what you need rather than making you remember it.
Questions
What is Miller's Law?
Miller's law is the observation that the average person can hold roughly seven items in working memory, making chunking and external memory aids essential in design.
Why do you use Miller's Law?
Because asking people to remember is asking them to fail. Interfaces should carry the load, not the user.
How do you use/apply Miller's Law?
Chunk information into small groups, keep visible context so nothing has to be memorised across steps, break long tasks into stages, and show rather than tell.
When do you use Miller's Law?
In forms, multi-step flows, data displays and any task that spans screens.
Who uses Miller's Law?
UX designers, content designers and anyone structuring information.
