What is overlap?

Overlap is the number of Tolokers who should complete each task in the pool.

You can set overlap in the pool settings:

How to work via Toloka API

To change overlap using Toloka API, send a PATCH request with the updated overlap value:

curl -X PATCH 'https://toloka.dev/api/v1/task-suites/000012e4ca--62eadb541b54e36b45b7a117?open_pool=true' \
-H 'Authorization: ApiKey PlaceYourRealApiKey_Here' \
-H 'Content-Type: application/json' \
-d '{"overlap":5,"infinite_overlap":false}'

Refer to the Edit task suite overlap or priority section of the Toloka API documentation for more details about the request, its parameters, and possible responses. You will find examples of the requests for Toloka-Kit and other code samples there.

Tips and recommendations

Task typeRecommended overlap
Most tasks have automatic acceptancefrom 3 to 5
Simple task3
Reviewed task1

You can change overlap after the pool is started. To do this, open the pool editing mode and set the new overlap value. You don't need to restart the pool. Updating the settings is usually fast, but if there are many tasks, it may take several minutes.

Advanced overlap types

  • Dynamic overlap lets you change overlap depending on:

    • How well the Tolokers do on the task.
    • How well Tolokers' task responses match each other.

    This type of overlap helps you save money without reducing the quality of data labeling.

  • Selective majority vote verification allows you to set up majority vote check for only a portion of tasks.

    This type of overlap helps you save money and speed up pool completion.

Setting up the overlap for an individual task

You can set the overlap for each task using the TASK:overlap column values in the file with tasks.

To learn more, see the Tasks file structure section.

For developers


Can I do it like this: set a basic overlap of 2 Tolokers, then, if both Tolokers select the same task response, close the pool, but if they give different responses, show the task to one more user?
Is there a cross-check feature for tasks?
Why is the maximum number of submitted assignments in the progress bar less than the total number of uploaded tasks?
How does counting work if I set `overlap = 3` in the pool and `task response threshold = 3` in the majority vote?
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Last updated: August 24, 2023

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