This page describes helpful techniques for improving search accuracy and relevance.

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Rerank results

Reranking is used as part of a two-stage vector retrieval process to improve the quality of results. You first query an index for a given number of relevant results, and then you send the query and results to a reranking model. The reranking model scores the results based on their semantic relevance to the query and returns a new, more accurate ranking. This approach is one of the simplest methods for improving quality in retrieval augmented generation (RAG) pipelines. Pinecone provides hosted reranking models so it’s easy to manage two-stage vector retrieval on a single platform. You can use a hosted model to rerank results as an integrated part of a query, or you can use a hosted model to rerank results as a standalone operation.

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Filter by metadata

Every record in an index must contain an ID and a dense or sparse vector, depending on the type of index. In addition, you can include metadata key-value pairs to store related information or context. When you search the index, you can then include a metadata filter to limit the search to records matching a filter expression. For example, if an index contains records about books, you could use a metadata field to associate each record with a genre, like "genre": "fiction" or "genre": "poetry". When you query the index, you could then use a metadata filter to limit your search to records related to a specific genre. For more details, see Filter by metadata. Semantic search and lexical search are powerful information retrieval techniques, but each has notable limitations. For example, semantic search can miss results based on exact keyword matches, especially in scenarios involving domain-specific terminology, while lexical search can miss results based on relationships, such as synonyms and paraphrases. To lift these limitations, you can search both dense and sparse indexes, combine the results from both, and use one of Pinecone’s hosted reranking models to assign a unified relevance score, reorder the result accordingly, and return the most relevant matches. This is often called hybrid search or cascading retrieval. For more details, see Hybrid search.

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Explore chunking strategies

You can chunk your content in different ways to get better results. Consider factors like the length of the content, the complexity of queries, and how results will be used in your application. For more details, see Chunking strategies.