# Working memory limits

A working memory is a part of our cognitive system where we hold temporary information and process them. There are limits to our working memory:

  1. How long we can hold the information
  2. How many pieces of information we can hold and process

We can't hold the information in our working memory for more than 30 seconds. There are a couple of answers to how many information we can hold and process. Many references would refer to the number 7 (Miller). A more recent study points that our limit is more like a maximum of 4 (Cowan).

# References

Ahrens, How to Take Smart Notes (p. 68).

Our short-term memory is also limited. We need strategies not to waste its capacity with thoughts we can better delegate to an external system. While the estimations of our long-term memory capacity are wildly diverse and rather speculative, psychologists used to tend to agree on a very specific number when it came to short-term memory: We can hold a maximum of seven things in our head at the same time, plus/minus two (Miller 1956).

Miller, George A. ‘The Magical Number Seven, plus or Minus Two: Some Limits on Our Capacity for Processing Information.’ Psychological Review, vol. 63, no. 2, 1956, pp. 81–97. DOI.org (Crossref), doi:10.1037/h0043158.

Cowan, Nelson. ‘The Magical Number 4 in Short-Term Memory: A Reconsideration of Mental Storage Capacity’. Behavioral and Brain Sciences, vol. 24, no. 1, Feb. 2001, pp. 87–114. DOI.org (Crossref), doi:10.1017/S0140525X01003922.

Scientific Secrets for Raising Kids Who Thrive Audiobook | Peter M. Vishton, The Great Courses | Audible.co.uk (Downloadable PDF)

We have a short-term memory that is limited in size to something like seven digits, words, or other units. The only way to hang on to information for a longer time period is to create a more durable representation, either by writing it down or encoding a long-term memory of it.