> ## 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.

# Size ratio

> Learn how to use the size ratio test

## Definition

The size ratio test allows you to set a threshold on the the ratio between the number of rows in the validation and training datasets.

## Taxonomy

* **Task types**: LLM, tabular classification, tabular regression, text classification.
* **Availability**: <Tooltip tip="Continuously evaluate your models and datasets as you iterate on their versions.">development</Tooltip>.

## Why it matters

* It is important that your model is validated on a sufficient amount of unseen data. If the validation set is too small compared to the training set, it may not adequately represent the variety of data the model will encounter in the real world, leading to overfitting.
* The size ratio can also helps ensure the statistical significance of the validation results.

## Test configuration examples

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

<CodeGroup>
  ```json Development theme={null}
  [
    {
      "name": "Size ratio between validation and training datasets of at least 0.2",
      "description": "Asserts that the size of the validation dataset is at least 20% of the size of the training dataset",
      "type": "consistency",
      "subtype": "sizeRatio",
      "thresholds": [
        {
          "insightName": "sizeRatio",
          "insightParameters": null,
          "measurement": "sizeRatio",
          "operator": ">=",
          "value": 0.2
        }
      ],
      "subpopulationFilters": null,
      "mode": "development",
      "usesValidationDataset": true,
      "usesTrainingDataset": true,
      "usesMlModel": false,
      "syncId": "b4dee7dc-4f15-48ca-a282-63e2c04e0689" // Some unique id
    }
  ]
  ```
</CodeGroup>

## Related

* [Number of rows test](/tests/integrity/row-count).