Score search terms by inverse document frequency \(IDF\)

task brazil Updated Sep 10, 2026 1 min read enable-IDF-scoring.md

Enable term frequency–inverse document frequency (TF-IDF) to increase the search result scores of search terms that appear more frequently in a document, but less frequently in the whole collection of searchable documents.

Before you begin

To enable TF-IDF scoring, a text index must be present for the table. Make sure that text indexing is enabled for the table before changing the query mode. See Configure a table for indexing and searching.

Role required: ts_admin or admin

About this task

Administrators can enable TF-IDF scoring on a table to improve search results. The Knowledge table [kb_knowledge] has TF-IDF scoring enabled by default.

Note: This task requires that you regenerate an index and therefore should be done with system performance in mind. Regenerating an index may take a while to complete depending on table size and other factors. You may notice performance degradation or incomplete search results while the system regenerates the index.

Procedure

Navigate to the system dictionary and open the entry for the desired table.
In the Attributes related list, select New.
In the Attributes field, select Text search Enable IDF.
Select Submit.

The Enable IDF Score check box in the table's text index record can now be configured.
Navigate to All > System Definition > Text Indexes.
Open the text index created for the table.
Select Enable IDF Score.
Under Related Links, select Regenerate Document Frequency.

Regenerating document frequency is a one-time task. Regenerate document frequency when TF-IDF scoring is first enabled for a table.
Configure the desired notification and select OK.

Parent Topic:Zing computes document scores using three components

Related topics

Set the relative weight of a field

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---
title: Score search terms by inverse document frequency \(IDF\)
description: Enable term frequency–inverse document frequency \(TF-IDF\) to increase the search result scores of search terms that appear more frequently in a document, but less frequently in the whole collection of searchable documents.
locale: en-US
canonical_url: https://www.servicenow.com/docs/r/platform-administration/search-administration/enable-IDF-scoring.html
release: brazil
product: Search Administration
classification: search-administration
topic_type: task
last_updated: "2026-09-10"
reading_time_minutes: 1
breadcrumb: [Zing computes document scores using three components, Zing text indexing and search engine, Search administration, Configure core features, Administer the ServiceNow AI Platform]
---

# Score search terms by inverse document frequency \(IDF\)

Enable term frequency–inverse document frequency \(TF-IDF\) to increase the search result scores of search terms that appear more frequently in a document, but less frequently in the whole collection of searchable documents.

## Before you begin

To enable TF-IDF scoring, a text index must be present for the table. Make sure that text indexing is enabled for the table before changing the query mode. See [Configure a table for indexing and searching](https://raw.githubusercontent.com/ServiceNow/ServiceNowDocs/brazil/markdown/platform-administration/search-administration/configure-single-table-for-indexing.md).

Role required: ts\_admin or admin

## About this task

Administrators can enable TF-IDF scoring on a table to improve search results. The Knowledge table \[kb\_knowledge\] has TF-IDF scoring enabled by default.

**Note:** This task requires that you regenerate an index and therefore should be done with system performance in mind. Regenerating an index may take a while to complete depending on table size and other factors. You may notice performance degradation or incomplete search results while the system regenerates the index.

## Procedure

1. Navigate to the [system dictionary](https://raw.githubusercontent.com/ServiceNow/ServiceNowDocs/brazil/markdown/platform-administration/table-administration-and-data-management/c_SystemDictionary.md) and open the entry for the desired table.

2. In the **Attributes** related list, select **New**.

3. In the **Attributes** field, select **Text search Enable IDF**.

4. Select **Submit**.

The **Enable IDF Score** check box in the table's text index record can now be configured.

5. Navigate to **All** &gt; **System Definition** &gt; **Text Indexes**.

6. Open the text index created for the table.

7. Select **Enable IDF Score**.

8. Under **Related Links**, select **Regenerate Document Frequency**.

Regenerating document frequency is a one-time task. Regenerate document frequency when TF-IDF scoring is first enabled for a table.

9. Configure the desired notification and select **OK**.

**Parent Topic:**[Zing computes document scores using three components](https://raw.githubusercontent.com/ServiceNow/ServiceNowDocs/brazil/markdown/platform-administration/search-administration/c_DocumentScoring.md)

**Related topics**

[Set the relative weight of a field]()