Overview
The average person can only keep 7 (plus or minus 2) items in their working memory.
Takeaways
- Don’t use the “magical number seven” to justify unnecessary design limitations.
- Organize content into smaller chunks to help users process, understand, and memorize easily.
- Remember that short-term memory capacity will vary per individual, based on their prior knowledge and situational context.
Origins
In 1956, George Miller asserted that the span of immediate memory and absolute judgment were both limited to around 7 pieces of information. The main unit of information is the bit, the amount of data necessary to make a choice between two equally likely alternatives. Likewise, 4 bits of information is a decision between 16 binary alternatives (4 successive binary decisions). The point where confusion creates an incorrect judgment is the channel capacity. In other words, the quantity of bits which can be transmitted reliably through a channel, within a certain amount of time.
Further Reading
Related
Hick’s Law
The time it takes to make a decision increases with the number and complexity of choices.
Aesthetic-Usability Effect
Users often perceive aesthetically pleasing design as design that’s more usable.
Doherty Threshold
Productivity soars when a computer and its users interact at a pace (<400ms) that ensures that neither has to wait on the other.