# Reranking · Glossary
A second retrieval step in which a more precise model reorders an initial set of search results by relevance to the query.
[Glossary](/glossary) · Agentic systems and generative AI

# Reranking

     A second retrieval step in which a more precise model reorders an initial set of search results by relevance to the query. It improves the quality of the few passages that are actually passed to a language model.

## Why it matters

     Initial retrieval is designed to be fast across large collections, so its ranking is approximate. Reranking spends more effort on a short list, which usually improves answer quality in retrieval-augmented generation without changing the underlying index.

     It adds latency and cost per query, so its benefit should be measured against the organisation’s own questions and documents.

## In practice

     For example, a pharmaceutical regulatory team’s assistant might retrieve fifty candidate passages from submission documents, rerank them, and pass only the top five to the model, improving the precision of cited answers.

## Where Rodan fits

     Rodan tests retrieval pipelines end to end, including reranking, as part of [AI and Decision Systems](https://rodan.io/what-we-build/ai-decision-systems) delivery.

## Related terms

- [Hybrid search](/glossary/hybrid-search)

- [Semantic search](/glossary/semantic-search)

- [Retrieval-augmented generation (RAG)](/glossary#retrieval-augmented-generation)

- [AI evaluation (evals)](/glossary#ai-evaluation)
HTML: https://rodan.io/glossary/reranking