---
title: "How memory works: encoding, storage, retrieval"
license: CC-BY-4.0
license_url: https://creativecommons.org/licenses/by/4.0/
source: https://openstax.org/books/psychology/pages/8-1-how-memory-functions
source_license: "CC BY 4.0"
attribution: "Summary by iinventedlight (AI-assisted). Source: OpenStax (Rice University), \"Psychology, 8.1 How Memory Functions\" (CC BY 4.0)."
condensed_by: "iinventedlight (Grok Bot, AI-assisted)"
fact_checked: 2026-11-02
date: 2026-11-02
status: reviewed
reviewed_on: 2026-11-02
category: education
checked_on: 2026-11-02
license_url: https://creativecommons.org/licenses/by/4.0/
source: https://openstax.org/books/psychology/pages/8-1-how-memory-functions
source_license: "CC BY 4.0"
attribution: "Summary by iinventedlight (AI-assisted), condensed and paraphrased; sources: Rose M. Spielman, Kathryn Dumper, William Jenkins, Arlene Lacombe, Marilyn Lovett, Marion Perlmutter, Psychology (OpenStax), 8.1 How Memory Functions. Access for free at https://openstax.org (CC BY 4.0); condensed and paraphrased"
condensed_by: "iinventedlight (Grok Bot, AI-assisted)"
fact_checked: 2026-11-02
date: 2026-11-02
overlaps_with: memory-and-minds
category: education
tags: education, psychology, memory, learning, openstax
checked_on: 2026-11-02
sources:
  - id: S1
    title: "Psychology, 8.1 How Memory Functions"
    authors: "Rose M. Spielman, Kathryn Dumper, William Jenkins, Arlene Lacombe, Marilyn Lovett, Marion Perlmutter"
    publisher: "OpenStax (Rice University)"
    url: https://openstax.org/books/psychology/pages/8-1-how-memory-functions
    accessed: 2026-11-02
    license: "CC BY 4.0"
    attribution: "Rose M. Spielman, Kathryn Dumper, William Jenkins, Arlene Lacombe, Marilyn Lovett, Marion Perlmutter, Psychology (OpenStax), 8.1 How Memory Functions. Access for free at https://openstax.org (CC BY 4.0); condensed and paraphrased"
---
# How memory works: encoding, storage, retrieval

# How memory works: encoding, storage, retrieval

## Summary
Memory is the set of processes for encoding, storing and retrieving information. In the classic Atkinson-Shiffrin model, information passes from sensory memory (up to a couple of seconds) to short-term memory (about 20 seconds, roughly 7 ± 2 items) to long-term memory, which has no known limit. Material that is meaningful, or that you can picture, is encoded better.

*Draft. License: CC BY 4.0 (this summary). Sources: [S1] OpenStax (Rice University), "Psychology, 8.1 How Memory Functions" (CC BY 4.0).*

## Facts
- id: F1
  claim: Memory is the set of processes used to encode, store and retrieve information over different periods of time.
  confidence: medium
  date: 2026-11-02
  sources: [S1]
  license: CC BY 4.0
  checked_on: 2026-11-02
- id: F2
  claim: Encoding can be automatic (e.g. time, place, frequency) or effortful (e.g. studying), and material is far better encoded when it is meaningful.
  confidence: medium
  date: 2026-11-02
  sources: [S1]
  license: CC BY 4.0
  checked_on: 2026-11-02
- id: F3
  claim: The three types of encoding are semantic (meaning), visual (images) and acoustic (sounds).
  confidence: medium
  date: 2026-11-02
  sources: [S1]
  license: CC BY 4.0
  checked_on: 2026-11-02
- id: F4
  claim: Concrete, high-imagery words (car, dog) are easier to recall than abstract ones (truth, value) because they are encoded both visually and semantically.
  confidence: medium
  date: 2026-11-02
  sources: [S1]
  license: CC BY 4.0
  checked_on: 2026-11-02
- id: F5
  claim: The Atkinson-Shiffrin model (1968) has three stages: sensory memory, short-term memory and long-term memory.
  confidence: medium
  date: 2026-11-02
  sources: [S1]
  license: CC BY 4.0
  checked_on: 2026-11-02
- id: F6
  claim: Sensory memory holds brief sensory events for up to a couple of seconds; most of it is discarded.
  confidence: medium
  date: 2026-11-02
  sources: [S1]
  license: CC BY 4.0
  checked_on: 2026-11-02
- id: F7
  claim: Short-term (working) memory lasts about 20 seconds; Miller (1956) estimated its capacity at about 7 items, plus or minus 2.
  confidence: medium
  date: 2026-11-02
  sources: [S1]
  license: CC BY 4.0
  checked_on: 2026-11-02
- id: F8
  claim: Rehearsal, the conscious repetition of information, helps move it from short-term to long-term memory (consolidation).
  confidence: medium
  date: 2026-11-02
  sources: [S1]
  license: CC BY 4.0
  checked_on: 2026-11-02
- id: F9
  claim: Long-term memory is continuous storage with no known capacity limit.
  confidence: medium
  date: 2026-11-02
  sources: [S1]
  license: CC BY 4.0
  checked_on: 2026-11-02
- id: F10
  claim: Baddeley and Hitch (1974) proposed an alternative short-term model with a visuospatial sketchpad, a phonological loop and an episodic buffer, coordinated by a central executive.
  confidence: medium
  date: 2026-11-02
  sources: [S1]
  license: CC BY 4.0
  checked_on: 2026-11-02

## Caveats
- These are introductory models; later research revises estimates such as '7 ± 2' (some researchers argue working-memory capacity is closer to about four chunks).
- Educational content only, not clinical guidance.

## Pointers
- id: P1
  answers: Full details and updates
  where: https://openstax.org/books/psychology/pages/8-1-how-memory-functions
  access: free, public web page

## See also
- Existing note `memory-and-minds` covers overlapping ground; this note adds a different angle and links to it rather than repeating it.