LESSON 83 / 215·2 min readIntermediate

Long-term, semantic, episodic, and user-profile memory

Should knowConcept lesson
01 Understand02 Recall03 Prepare

Words made simple

A few useful meanings before you read the explanation.

Retrieval
Finding and fetching information that is useful for the current question.
Agent
An application that uses a model to choose its next action within defined limits. It can use tools and continue through several steps.
Persistence
Saving information so it remains available after a request ends or a process restarts.
More words from this lesson
Authorization
Checking what that identity is allowed to read or do. Being logged in does not grant access to every record.
Overlap
Repeating a small amount of text in neighboring document chunks to help retain context near their boundaries.

Overview

  • Long-term memory stores selected information beyond one task.
  • Semantic memory contains facts or preferences; episodic memory records past events; user-profile memory contains explicit attributes such as preferred language.
  • These categories overlap and should be defined by application requirements rather than mystical model capabilities.

Why this matters

Returning users benefit from relevant continuity, and agents may need prior verified task outcomes.

An everyday example

A customer profile stores contact preferences; a service history stores prior visits.

A technical example

Profile: preferredLanguage="Gujarati"; episode: claimDraftReviewed with date, source, and user ID.

How it works

  1. Identify candidate memory
  2. Verify/confirm
  3. Attach source, scope, and timestamp
  4. Persist with retention
  5. Retrieve only relevant authorized entries
  6. Update/delete on correction.

Architecture and flow

Verified event/preference → scoped memory store → relevance retrieval → bounded context.

The insurance assistant example

Remember the customer's chosen communication language, but never assume last year's policy remains active.

When to use it

Clear repeated personalization or task-continuity needs with user-visible controls.

When to avoid it

Do not store sensitive medical details or inferred personality labels just because they appeared in chat.

Interview answer

“Long-term memory is curated, scoped, source-backed application data. I distinguish preferences and past events from current business facts.”

Benefits, trade-offs, and production considerations

  • Memory poisoning means malicious or incorrect content becomes future trusted context.
  • Require provenance and write policy, set expiry, allow user correction, and avoid treating retrieval similarity as memory truth.
PAUSE & RECALL

Can you explain it without the notes?

Long-term, semantic, episodic, and user-profile memory

Use your own words. Explain an example and one limitation before checking the explanation.

Check your explanation

Long-term memory stores selected information beyond one task. Semantic memory contains facts or preferences; episodic memory records past events; user-profile memory contains explicit attributes such as preferred language. These categories overlap and should…

CONNECT IT TO YOUR INTERVIEW

Turn this concept into a clear answer.

Practice this concept
YOUR NEXT STEP

Keep connecting the ideas.

Next lesson: State persistence and checkpoints

Adapted from 13_AI.MD · “Long-term, semantic, episodic, and user-profile memory”. Examples are study fragments; framework behavior can depend on your version.