Working memory
Working memory is the small amount of information a person can hold active and manipulate at one time, as distinct from long-term memory, which is storage. George Miller observed in 1956 that people could hold roughly seven items, give or take two, though the modern estimate is lower, around four chunks, and the number depends heavily on how the material is grouped. Alan Baddeley and Graham Hitch proposed in 1974 that it is not a single store but several components: a verbal loop for rehearsing sounds and words, a visual sketchpad for images and space, and a central executive that allocates attention between them. What counts as a single item is flexible, which is why grouping digits into familiar chunks lets people hold far more than seven digits.
Why it matters
It is the hard limit on how much a person can juggle at once, and it explains why instructions, interfaces, and lessons fail when they exceed it.
Also written: short-term memory, working memory capacity
Where it comes up
Read about Working memory on Wikipedia
Sources
- Working memory Wikipedia
- The Magical Number Seven, Plus or Minus Two Classics in the History of Psychology, York UniversityMiller's 1956 paper, one of the founding documents of cognitive psychology.
- Baddeley's model of working memory Wikipedia
