# Categorical

The Categorical generator shuffles the existing values within a field while maintaining the overall frequency of the values. It disassociates the values from other pieces of data. Note that NULL is considered a separate value.

For example, a column contains the values `Small`, `Medium`, and `Large`. `Small` appears 3 times, `Medium` appears 4 times, and `Large` appears 5 times. In the output data, each value still appears the same number of times, but the values are shuffled to different rows.

This generator is optimized for categories with fewer than 10,000 unique values. If your underlying data has more unique values (for example, your field is populated by freeform text entry), we recommend that you use the [Character Scramble](https://docs.tonic.ai/app/generation/generators/generator-reference/character-scramble) or [Custom Categorical](https://docs.tonic.ai/app/generation/generators/generator-reference/custom-categorical) generator.

## Characteristics <a href="#categorical-characteristics" id="categorical-characteristics"></a>

<table data-header-hidden><thead><tr><th valign="top"></th><th valign="top"></th></tr></thead><tbody><tr><td valign="top"><strong>Consistency</strong></td><td valign="top">No, cannot be made consistent.</td></tr><tr><td valign="top"><strong>Linking</strong></td><td valign="top">Yes, can be linked.</td></tr><tr><td valign="top"><strong>Differential privacy</strong></td><td valign="top">Configurable</td></tr><tr><td valign="top"><strong>Data-free</strong></td><td valign="top">No</td></tr><tr><td valign="top"><strong>Allowed for primary keys</strong></td><td valign="top">No</td></tr><tr><td valign="top"><strong>Allowed for unique columns</strong></td><td valign="top">No</td></tr><tr><td valign="top"><strong>Uses format-preserving encryption (FPE)</strong></td><td valign="top">No</td></tr><tr><td valign="top"><strong>Privacy ranking</strong></td><td valign="top"><ul><li>2 if differential privacy enabled</li><li>3 if differential privacy not enabled</li></ul></td></tr><tr><td valign="top"><strong>Generator ID (for the API)</strong></td><td valign="top"><a href="../../../api/quick-start-guide/tonic-api-generator-assignment/generator-api-reference/generator-api-ref-categorical"><code>CategoricalGenerator</code></a></td></tr></tbody></table>

## How to configure <a href="#categorical-configure" id="categorical-configure"></a>

To configure the generator:

1. From the **Link To** dropdown, select the columns to link to the current column.\
   \
   You can select from other columns that use the Categorical generator.
2. Toggle the **Differential Privacy** setting to indicate whether to make the output data differentially private.\
   \
   By default, differential privacy is disabled.
3. If [Structural data encryption](https://docs.tonic.ai/app/generation/generators-assign-config/generators-data-encryption-config) is enabled, then to use it for this column, in the advanced options section, toggle **Use data encryption process** to the on position.