---
sourceDocument: Xanadu Enable AI
sourceDocumentLink: https://servicenow-prod.fluidtopics.net/r/xanadu/intelligent-experiences

 Release :

    - xanadu

ft:locale :

    - en-US

ft:publication_title :

    - Xanadu Enable AI

ft:clusterId :

    - platai

bundleId :

    - platai

workflow :

    - Platform


---

# Retriever chunking and reranking

# Retriever chunking and reranking {#ariaid-title1}

* Release version: Xanadu
* 
* Updated October 7, 2024
* 
* ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 1 minute to read

When you're building a skill prompt that uses a retriever you can use chunking and reranking to enhance the accuracy and relevance of your responses.

## Before you begin

Role required: sn_skill_builder.admin

## About this task

To set up the chunking and reranking options for a retriever, you must have a retriever tool added to your skill with the Hybrid or Semantic search criteria. The following steps
come after the semantic configuration in [Add a retriever](https://servicenow-prod.fluidtopics.net/3KwiZp7wSS4gpAgkFY9pZQ "Add a retriever to your prompt to augment and add context to your prompts with AI search results.").

## Procedure

1. Navigate to AllNow Assist Skill KitHome.
2. Select the skill that you're adding a retriever to.
3. [Add a retriever](https://servicenow-prod.fluidtopics.net/3KwiZp7wSS4gpAgkFY9pZQ "Add a retriever to your prompt to augment and add context to your prompts with AI search results.").
4. On the form, fill in the fields.  
   {#retriever-chunking__table_zcj_zmc_fdc__entry__2}

   | Field | Description |
   |-|-|
   | Max number of chunks per document | The maximum number of chunks that you want returned per document. The default value is 10. |
   | Chunking strategy | * Fixed size Fixed size breaks down the full text into smaller passages. You can choose the passage size limit in number of words or number of sentences. * Small to big Small to big enables you to choose the top K best matched indexed chunks and expand them to include surrounding chunks. Then the expanded chunks are linked together into a large text and broken into smaller passages. Don't use the small to big chunking strategy if you're using full text or truncate index chunking configuration. {#retriever-chunking__ul_a2y_x4c_fdc} |
   | Chunking unit | * Words * Sentences {#retriever-chunking__ul_zsb_z4c_fdc} |
   | Chunk size | The size of the chunks that are returned. The default value for word size is 750. The default value for sentence size is 40. |
   | Expanded snippet size | The size of the expanded chunks that are included when you select the small to big chunking strategy. |
   | Top K results | The number of chunks the reranker returns. |
   [Table 1. Chunking and reranking form]

   {#retriever-chunking__table_zcj_zmc_fdc}
5. Select Next.
6. Select the type of condition that you want to be evaluated when the tool is executed.
7. Select Next.
8. Review the selections that you made for the tool and select Add tool.

*[\>]: and then