Implementing Relative Score Fusion for Hybrid Search in Elasticsearch

Elastic Stack Elasticsearch
1

Hello Elasticsearch Community,

I'm interested in implementing Relative Score Fusion (RSF) directly in Elasticsearch to combine BM25 and kNN search results with weighted rankings based on query length or type. I want to avoid relying heavily on application-side logic and perform this fusion within Elasticsearch itself.

What are the best practices for achieving this? Are there specific techniques or built-in features in Elasticsearch that can facilitate score normalization and weighted combination directly within queries?

Any guidance or examples would be greatly appreciated!

Thank you!

Reference: https://weaviate.io/blog/hybrid-search-fusion-algorithms

2

Hi @ayubSubhaniya,

See if these resources could help:

3

Thanks @Alex_Salgado-Elastic , I went through that docs it helps a bit but what I was looking for is a improved version over RRF, that is reciprocal score fusion.