Miller's Law

Observation that an individual normally can retain or process only seven give or take two (7±2) items (chunks) of information in their correct serial-order, in his or her short-term (15 to 30 seconds duration) or 'working' memory. Reported by the Princeton University's cognitive psychologist George A. Miller in 1956, it is accepted more as a rule of thumb than a scientifically proven fact. Also called Miller's Magic Number.