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

# Extraction coverage

**Note:** If you're familiar with extraction coverage, this detailed topic is for you. If you're new to Sensible, see [Monitoring extractions](/best-practices/metrics).

Extraction coverage measures how fully an extraction captures your target data from the document. Sensible calculates the coverage for each extraction as follows:

`coverage` = (`non-null fields extracted` <br />- `validation penalties` ) ÷ (`total fields extracted`)

Where:

* `validation penalties` = sum of [validation](/best-practices/validate-extractions) errors and warnings. Errors are 1 penalty point and warnings are 0.5 points.

For example, if an extraction has the following properties:

* num of non-null fields extracted = 18
* num fields extracted= 20
* num of fields with validation errors = 1
* num of fields with validation warnings = 4

Then its coverage is 75% : (18 - 1 - 2) / 20 = 0.75.

To view an individual extraction's coverage, click **Dashboard** and scroll to the **Recent** section:

![Click to enlarge](https://mintlify.s3-us-west-1.amazonaws.com/sensible/assets/v0/images/screenshots/dashboard_coverage_1.png)

In the preceding screenshot, get a coverage breakdown by viewing the extraction. You can view the extraction by clicking the extraction date in the **Recent extractions** column or downloading the Excel file.

For example, in the preceding screenshot, you can click `Sept 25, 2023, 7:30 PM` in the **Created** column to count the extracted fields in the SenseML editor and find that the score of `61.1%` means that 33 of 54 total fields output were valid and non-null. Or, you can retrieve the information from the [Sensible API](/api-reference/extraction/retrieve-extractions/retrieving-results) or SDK. The following code sample shows an except from an API response with the `validation_summary` used to calculate the `coverage` for the Sept 25 extraction:

```
{
	"id": "efe99816-0e5b-11eb-b720-295a6fba723e", // extraction ID
	"validation_summary": {
		"fields": 54, //total fields
		"fields_present": 33, //non-null fields
		"errors": 0, //validation errors and warnings
		"warnings": 0,
		"skipped": 0
	},
	"coverage": 0.611 // extraction coverage score calculated from validation_summary
```

**Notes**

* Sensible excludes fields listed in the Suppress Output method when calculating the coverage.
* Sensible includes fields output in [sections](/senseml-reference/sections/index-sections) when calculating the coverage.
* The overall coverage for a portfolio document is the average of all subdocument coverages.