The New Magic Rule of 4

George A. Miller's 1956 paper, "The Magical Number Seven, Plus or Minus Two," suggests that the average person can hold about 7 items (ranging from 5 to 9) in their short-term memory. Miller's law suggests how our reliable short-term memory is limited to remembering no more than seven information "objects," and how information retention lasts no longer than about 30 seconds.

This concept is often referred to as Miller's Law, or Miller's Magic Number.

However, more recent research indicates that the actual capacity may be closer to 4 items. For a review of visual memory capacity see Brady, T.F et. al. (2011) Journal of Vision

Given these findings, it would be advisable for managers to limit verbal instructions to about 3 to 4 items at a time to enhance comprehension and retention.