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Participant Eligibility Requirements

Prolific offers Eligibility Requirements to limit access to your Task (or Study, as Prolific calls it) to fitting Participants only. These are similar to Mephisto's qualifications, except they exist in Prolific's cloud, not your local Mephisto DB. This can be helpful in the beginning, when you're still building a pool of locally saved known workers.

As a technicality, filtering by Mephisto's Qualifications in Prolific is accomplished via creating a disposable (and dynamically updated) Eligible Participant Group (EGP) on Prolific, that contains all known workers satisfying Mephisto qualifications. Mephisto automatically generates and passes that EGP id to Prolific (as a ParticipantGroupEligibilityRequirement Study requirement), and when Task is complete, Mephisto deletes that EPG.

When usingseveral Eligibility Requirements together (e.g. CustomBlacklistEligibilityRequirement, CustomWhitelistEligibilityRequirement, and Mephisto qualifications), then Participants will be selected by intersecting all of these requirements.

Usage​

You can specify Prolific qualifications via Task config file, or directly in TaskRun shared state.

Usage in shared state​

Shared state can handle Prolific-supported qualifications. Example in run_task.py:

shared_state.prolific_specific_qualifications = [
    {
        "name": "AgeRangeEligibilityRequirement",
        "min_age": 18,
        "max_age": 100,
    },
]

shared_state.qualifications = [
    make_qualification_dict("sample_qual_name", QUAL_GREATER_EQUAL, 1),
]

Usage in task config​

Prolific-supported requirements can be specified in Hydra YAML Task config file, under the key prolific_eligibility_requirements:

mephisto:
  provider:
    prolific_eligibility_requirements:
      - name: "AgeRangeEligibilityRequirement"
        min_age: 10
        max_age: 20

Supported Eligibility Requirements​

Mephisto currently supports the following Eligibility Requirements under SharedState.prolific_specific_qualifications:

[
    {
        "name": "AgeRangeEligibilityRequirement",
        "min_age": "<value>",
        "max_age": "<value>",
    },
    {
        "name": "ApprovalNumbersEligibilityRequirement",
        "minimum_approvals": "<value>",
        "maximum_approvals": "<value>",
    },
    {
        "name": "ApprovalRateEligibilityRequirement",
        "minimum_approval_rate": "<value>",
        "maximum_approval_rate": "<value>",
    },
    {
        "name": "CustomBlacklistEligibilityRequirement",
        "black_list": "<value>",
    },
    {
        "name": "CustomWhitelistEligibilityRequirement",
        "white_list": "<value>",
    },
    {
        "name": "JoinedBeforeEligibilityRequirement",
        "joined_before": "<value>",
    },
    {
        "name": "ParticipantGroupEligibilityRequirement",
        "id": "<value>",
    },
]

NOTE: this list (last updated 2023.07.11) is derived from list of available classes in mephisto/abstractions/providers/prolific/api/eligibility_requirement_classes.

Block and Allow lists​

Prolific provides a way to limit Study participants based on their IDs via EGPs called prolific_allow_list_group_name and prolific_block_list_group_name:

  • Manual allow list is applied via CustomWhitelistEligibilityRequirement
    • This can be useful when testing your Task, and limiting its visibility to only a few test workers
  • Manual block list is applied via CustomBlacklistEligibilityRequirement
    - We do not recommend using manual block list directly, because we auto-compose it during every TaskRun,
    based on is_blocked column in the local datastore.