Semantic Memory

intermediate
Memory TypesLast updated: 2025-01-15
Also known as: factual memory, knowledge memory

What is Semantic Memory?


Semantic memory is a type of long-term memory that stores general knowledge, facts, and concepts independent of specific experiences. Unlike episodic memory which records events, semantic memory contains information abstracted from particular instances.


Examples in AI Agents


Semantic memory in AI agents might include:


  • User preferences ("prefers Python over JavaScript")
  • Learned facts ("user works at Acme Corp")
  • Domain knowledge ("the API rate limit is 100 requests/minute")
  • Relationship information ("Alice is Bob's manager")

  • Semantic vs Episodic Memory


    | Aspect | Semantic | Episodic |

    |--------|----------|----------|

    | Content | Facts & concepts | Events & experiences |

    | Time | Context-independent | Time-stamped |

    | Example | "User prefers dark mode" | "User asked about dark mode on Jan 15" |


    Building Semantic Memory


    Agents build semantic memory through:


  • Extracting facts from conversations
  • Consolidating repeated patterns
  • User profile updates
  • Knowledge base integration
  • Entity extraction and linking

  • Storage Approaches


    Common storage patterns for semantic memory:


  • **Key-Value Stores**: Simple fact storage
  • **Knowledge Graphs**: Relationship-rich representations
  • **Vector Databases**: Semantic similarity search
  • **Structured Databases**: Queryable fact tables

  • Retrieval Methods


    Semantic memories can be retrieved via:


  • Direct key lookup
  • Semantic similarity search
  • Graph traversal
  • SQL-like queries
  • Natural language queries

  • Memory Updates


    Unlike episodic memory which is append-only, semantic memory requires:


  • Conflict resolution for contradicting facts
  • Confidence scoring for uncertain information
  • Temporal validity tracking
  • Source attribution

  • Related Terms