AI-PRINCIPLES

Multi-Vector Retrieval

Multi-vector retrieval is a search approach that represents each document as multiple vectors rather than a single embedding. By assigning separate vectors to individual tokens or passages, techniques like late interaction compute fine-grained similarity between queries and documents at retrieval time. This produces more accurate matches than single-vector search, especially for complex queries where meaning varies across different parts of the text. Also known as: ColBERT, Late Interaction

1

Understand the Fundamentals

Multi-vector retrieval decomposes documents into token-level representations, enabling similarity matching at a granularity single-embedding models cannot reach. Understanding how late interaction works reveals why retrieval accuracy and computational cost trade off differently here.

2

Build with Multi-Vector Retrieval

The practical guides walk through building a multi-vector retrieval pipeline end to end, covering indexing strategies, storage trade-offs, and the engineering decisions that determine whether the accuracy gains justify the added infrastructure complexity.

4

Risks and Considerations

Finer-grained matching means larger indexes, higher costs, and more complex failure modes. Before adopting multi-vector retrieval, consider who bears the infrastructure burden and whether the accuracy gains actually reach every user group.