> ## Documentation Index
> Fetch the complete documentation index at: https://docs.openlayer.com/llms.txt
> Use this file to discover all available pages before exploring further.

# New categories

> Learn how to use the new categories test to detect new categories in your data

## Definition

The new categories test checks if there are new categories in the validation set which are not present in the training set for the categorical features.

## Taxonomy

* **Task types**: Tabular classification, tabular regression.
* **Availability**: development (Continuously evaluate your models and datasets as you iterate on their versions.).

## Why it matters

* If the validation set contains new categories, the model is not prepared to make good predictions for them.

## Test configuration examples

If you are writing a `tests.json`, here are a few valid configurations for the character length test:

```json Development theme={null}
[
  {
    "name": "No new categories",
    "description": "Asserts that there are no new categories in the current dataset if compared to the reference dataset",
    "type": "consistency",
    "subtype": "newCategoryCount",
    "thresholds": [
      {
        "insightName": "newCategories",
        "measurement": "newCategoryCount",
        "operator": "<=",
        "value": 0
      }
    ],
    "subpopulationFilters": null,
    "mode": "development",
    "usesValidationDataset": true,
    "usesTrainingDataset": true,
    "usesMlModel": false,
    "syncId": "b4dee7dc-4f15-48ca-a282-63e2c04e0689"
  }
]
```

```json Monitoring theme={null}
[
  {
    "name": "No new categories",
    "description": "Asserts that there are no new categories in the current dataset if compared to the reference dataset",
    "type": "consistency",
    "subtype": "newCategoryCount",
    "thresholds": [
      {
        "insightName": "newCategories",
        "measurement": "newCategoryCount",
        "operator": "<=",
        "value": 0
      }
    ],
    "subpopulationFilters": null,
    "mode": "monitoring",
    "usesProductionData": true,
    "evaluationWindow": 3600,
    "delayWindow": 0,
    "syncId": "b4dee7dc-4f15-48ca-a282-63e2c04e0689"
  }
]
```

## Related

* [New labels test](https://docs.openlayer.com/tests/consistency/new-label-count).


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