Searchplex ID Retrieval terminology registry

Method

Approximate Nearest Neighbor Search

Canonical ID https://id.searchplex.net/approximate-nearest-neighbor-search/

A search method that returns near-neighbor results using an approximation strategy to trade some exactness for lower latency, memory use, or computational cost.

Also called

  • ANN Search
  • ANNS

Scope

Approximate nearest neighbor search is widely used in vector search and dense retrieval systems, especially at large scale. It is not the same as vector search itself, because vector search may use exact search, approximate search, or other retrieval mechanisms.

Used for

Not equivalent to

  • Approximate Nearest Neighbor Search is not Dense Retrieval. Approximate nearest neighbor search is an efficiency method for neighbor lookup; dense retrieval is a retrieval approach using dense representations.
  • Approximate Nearest Neighbor Search is not HNSW. HNSW is one approximate nearest neighbor method; approximate nearest neighbor search is the broader method family.
  • Approximate Nearest Neighbor Search is not Vector Search. Approximate nearest neighbor search is one family of methods used in vector search; vector search is the broader practitioner term for retrieval over vector representations.

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