Basic terms

  • Researcher = Person who runs a study on Prolific in order to collect data
  • Participant = Person who participates in studies on Prolific in order to earn rewards
  • Prolific ID = Unique identifier assigned to each participant to ensure anonymity
  • Study = A survey, experiment, or task that a researcher runs on Prolific
  • Submission = A response to a study that has been submitted to Prolific by a participant


  • Top-up = The amount of money that researchers credit their Prolific accounts with
  • Commission = The amount Prolific charges for its services
  • Coupon = Discount that a researcher can apply to new studies
  • Invoice = Document that Prolific issues to its customers (ie., researchers) prior to a study, detailing the costs of the study
  • Receipt = Document that Prolific issues to its customers (ie., researchers) after a study, detailing the costs of the study

When setting up a study

  • Study name = the title you give your study, which is visible to participants
  • Study URL = The link to your study
  • Estimated completion time = How you estimate it will take participants to complete your study (ideally based on a pretest with Prolific participants)
  • Maximum allowed time = How much you give participants to complete your study
  • Callback URL / completion URL = A URL that researchers add to the end of their studies (Prolific provides a unique URL for each study). Participants will click this URL to prove that they have completed your study.
  • Completion code = A correct completion code shows that the participant clicked on your completion URL
  • NOCODE = If a participant completes the study on Prolific without entering the code or clicking on your completion url you will see NOCODE where the completion code should be. This doesn't mean that the participant didn't do your study. The participant may have just missed your completion url by mistake. However, if you see NOCODE you may want to confirm that the participant did your study correctly before approving their submission.
  • Prescreening criteria / screeners = Demographic criteria you can select under step 3 in the dashboard in order to filter participants
  • Eligible participants = Participants who fulfil the prescreening criteria you have selected (if you select none, then the eligible participants will be our entire participant pool)
  • Approval rate = the percentage of studies for which the participant has been approved. We use the upper bound of the 95% confidence interval to calculate approval rate.

When reviewing submissions

  • Approving a submission = Releasing the reward to the participant
  • Rejecting a submission = Denying to release a participant’s reward, which automatically opens the study to new participants
  • Unrejecting a submission = Reversing a rejection (i.e. approving a submission after all)
  • Timed out submission = Participant didn’t complete a study within the allotted time (which could have many different reasons: Something came up and the participant abandoned the study, the participant was completing it too conscientiously and as a result too slowly, etc.)
  • Returned submission = Participant actively decided not to finish a study
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