> ## 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.

# Sentence length

> Learn how to use the sentence length test to validate text sentence lengths

## Definition

The sentence length test validates that sentences in your text data fall within
specified length boundaries. You can set thresholds on both the maximum and minimum
sentence lengths to ensure text quality and consistency.

This test analyzes individual sentences within your text columns and measures their
character length, allowing you to detect overly long or short sentences that might
indicate data quality issues or generation problems.

## Taxonomy

* **Task types**: LLM, text classification.
* **Availability**: <Tooltip tip="Continuously evaluate your models and datasets as you iterate on their versions.">development</Tooltip>
  and <Tooltip tip="Monitor a model in production, measure its health, check for drifts and set up alerts.">monitoring</Tooltip>.

## Why it matters

* **Text quality assurance**: Ensures generated or processed text maintains appropriate sentence lengths for readability
* **Model output validation**: Prevents LLMs from generating extremely long run-on sentences or incomplete fragments
* **Data consistency**: Maintains uniform text formatting and structure across your dataset
* **User experience**: Ensures text outputs are readable and well-formatted for end users
* **Detection of generation issues**: Identifies when models produce malformed or truncated text

## Test configuration examples

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

<CodeGroup>
  ```json Development theme={null}
  [
    {
      "name": "Sentences not too long",
      "description": "Ensures no sentences exceed 200 characters to maintain readability",
      "type": "integrity",
      "subtype": "sentenceLength",
      "thresholds": [
        {
          "insightName": "sentenceLength",
          "measurement": "maxSentenceLength",
          "operator": "<=",
          "value": 200  // Maximum 200 characters per sentence
        }
      ],
      "subpopulationFilters": null,
      "mode": "development",
      "usesValidationDataset": true, // Apply test to the validation set
      "usesTrainingDataset": false,
      "usesMlModel": false,
      "syncId": "b4dee7dc-4f15-48ca-a282-63e2c04e0689" // Some unique id
    },
    {
      "name": "Sentences have minimum content",
      "description": "Ensures sentences are at least 10 characters to avoid fragments",
      "type": "integrity",
      "subtype": "sentenceLength",
      "thresholds": [
        {
          "insightName": "sentenceLength",
          "measurement": "minSentenceLength",
          "operator": ">=",
          "value": 10  // Minimum 10 characters per sentence
        }
      ],
      "subpopulationFilters": null,
      "mode": "development",
      "usesValidationDataset": true,
      "usesTrainingDataset": false,
      "usesMlModel": false,
      "syncId": "96622fba-ea00-4e42-8f42-5e8f5f60805f" // Some unique id
    },
    {
      "name": "Balanced sentence lengths",
      "description": "Ensures sentences are between 20-150 characters for optimal readability",
      "type": "integrity",
      "subtype": "sentenceLength",
      "thresholds": [
        {
          "insightName": "sentenceLength",
          "measurement": "minSentenceLength",
          "operator": ">=",
          "value": 20
        },
        {
          "insightName": "sentenceLength",
          "measurement": "maxSentenceLength",
          "operator": "<=",
          "value": 150
        }
      ],
      "subpopulationFilters": null,
      "mode": "development",
      "usesValidationDataset": true,
      "usesTrainingDataset": false,
      "usesMlModel": false,
      "syncId": "a1b2c3d4-e5f6-47g8-h9i0-j1k2l3m4n5o6" // Some unique id
    }
  ]
  ```

  ```json Monitoring theme={null}
  [
    {
      "name": "Generated text length monitoring",
      "description": "Monitors that generated sentences stay within acceptable length bounds",
      "type": "integrity",
      "subtype": "sentenceLength",
      "thresholds": [
        {
          "insightName": "sentenceLength",
          "measurement": "maxSentenceLength",
          "operator": "<=",
          "value": 300 // Allow slightly longer sentences in production
        }
      ],
      "subpopulationFilters": null,
      "mode": "monitoring",
      "usesProductionData": true,
      "evaluationWindow": 3600, // 1 hour
      "delayWindow": 0,
      "syncId": "b4dee7dc-4f15-48ca-a282-63e2c04e0689" // Some unique id
    },
    {
      "name": "Sentence completeness check",
      "description": "Alerts when sentences are suspiciously short, indicating potential truncation",
      "type": "integrity",
      "subtype": "sentenceLength",
      "thresholds": [
        {
          "insightName": "sentenceLength",
          "measurement": "minSentenceLength",
          "operator": ">=",
          "value": 5 // Very basic minimum to catch severe truncation
        }
      ],
      "subpopulationFilters": null,
      "mode": "monitoring",
      "usesProductionData": true,
      "evaluationWindow": 3600, // 1 hour
      "delayWindow": 0,
      "syncId": "96622fba-ea00-4e42-8f42-5e8f5f60805f" // Some unique id
    }
  ]
  ```
</CodeGroup>