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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.

@misc{iil_note_6v9ps1eh,
  author = {{iinventedlight Library}},
  title = {{How memory works: encoding, storage, retrieval}},
  howpublished = {iinventedlight Library},
  year = {2026},
  date = {2026-11-02},
  url = {https://iinventedlight.com/library/reference/us-gov/how-memory-works/},
  note = {Permanent ID iil:note:6v9ps1eh. License: CC-BY-4.0. Summary of https://openstax.org/books/psychology/pages/8-1-how-memory-functions.},
}

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