# How to combine default BM25 score of Elasticsearch and Dense Vectors similarity

**URL:** <https://discuss.elastic.co/t/how-to-combine-default-bm25-score-of-elasticsearch-and-dense-vectors-similarity/269614>\
**Category:** Elasticsearch\
**Created:** [April 8, 2021, 3:02pm UTC](https://discuss.elastic.co/t/how-to-combine-default-bm25-score-of-elasticsearch-and-dense-vectors-similarity/269614 "2021-04-08T15:02:07Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![xiaoma](https://avatars.discourse-cdn.com/v4/letter/x/45deac/32.png) [@xiaoma](https://discuss.elastic.co/u/xiaoma)\
**Post date:** [April 8, 2021, 3:02pm UTC](https://discuss.elastic.co/t/how-to-combine-default-bm25-score-of-elasticsearch-and-dense-vectors-similarity/269614/1 "2021-04-08T15:02:07Z")

</div>

i found a issue about how to combine the both default bm25 and vectors, but i try it and found the result was poor, is there any official document about how to combine default BM25 score of Elasticsearch and Dense Vectors similarity ? including how to set the important weight. Maybe more examples will help us to understand this powerful tools.

---

<div class="post-metadata">

**Author:** ![mayya](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/mayya/32/83147_2.png) [@mayya](https://discuss.elastic.co/u/mayya)\
**Post date:** [April 8, 2021, 7:48pm UTC](https://discuss.elastic.co/t/how-to-combine-default-bm25-score-of-elasticsearch-and-dense-vectors-similarity/269614/2 "2021-04-08T19:48:15Z")

</div>

There is no any official recipe how to set up these weights. You can frame this problem as as ML parameter optimization problem for your particular dataset.

I can refer you to our blog how this parameter optimization problem can be approached: [Improving search relevance with data-driven query optimization](https://www.elastic.co/blog/improving-search-relevance-with-data-driven-query-optimization)

---

<div class="post-metadata">

**Author:** ![xiaoma](https://avatars.discourse-cdn.com/v4/letter/x/45deac/32.png) [@xiaoma](https://discuss.elastic.co/u/xiaoma)\
**Post date:** [April 9, 2021, 1:11am UTC](https://discuss.elastic.co/t/how-to-combine-default-bm25-score-of-elasticsearch-and-dense-vectors-similarity/269614/3 "2021-04-09T01:11:57Z")

</div>

awesome! thank you very much

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [May 7, 2021, 1:12am UTC](https://discuss.elastic.co/t/how-to-combine-default-bm25-score-of-elasticsearch-and-dense-vectors-similarity/269614/4 "2021-05-07T01:12:41Z")

</div>

This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.