Contents:
1. Valid rejection reasons
2. Invalid rejection reasons
On Prolific, you have the option to reject participant submissions. However, please think carefully about whether the rejection is justified, and try to keep rejections to a minimum. Participants are penalized for rejections, and if they receive too many, they will be removed from the platform entirely. Please review all submissions holistically and remember that participants have spent time and effort taking your study.
See How do I reject or return a submission? for guidance on how to reject a submission.
Valid rejection reasons ✅
Completed exceptionally fast
• By 'exceptionally fast' we mean participants who are statistical outliers (3 standard deviations below the mean)
• This is the only criteria under which speed of submission can be used to reject
• Participants can't be rejected for not spending enough time on a specific page within your study
Skipped crucial questions
• These questions must be shown as force-response to the participant
• Please note that demographic questions do not fall under 'crucial questions' because participants have the right to withold such sensitive information (according to guidelines by the British Psychological Society)
Failed attention checks
• Participants must fail one attention check (for studies under 5 minutes) or multiple attention checks (for studies 5 minutes or longer)
• Please refer to our attention check policy for further guidance
Low effort
• The participant objectively demonstrated clear low-effort throughout the experiment, even when the required level of engagement was clearly specified
• For example, the participant was asked to write a paragraph but only put a few words or gibberish
Invalid rejection reasons ❌
Screened-out
• While we do allow researchers to validate their prescreeners applied on Prolific by asking the prescreening question(s) again in your survey (worded exactly as appeard on Prolific), any participant that fails this validation should be asked to return their submission rather than being rejected
• We don't allow within-study screening for criteria not applied in your Prolific prescreening
Completed too fast or too slow
• Participants' completion times vary around an average. They have variable reasing speeds and variable knowledge of keyboard shortcuts and other browser tools
• Please use more reliable measures to check for attention rather than completion time
Failed an internal measure
• For example, the participant's accuracy on a certain measure was not above an arbitrary threshold
• You're of course more than welcome to exclude these participants from your subsequent analysis; however, you'll still need to pay for their responses even if you can't use their data
• If you feel that your specific case merits a rejection, then please get in touch with our Research Support team using the button at the bottom of this page
Technical error
• Unfortunately, technical errors sometimes occur, but if it wasn't the participant's fault, then this is not a valid reason for rejection
• Please get in touch using the button at the bottom of this article if this happens and we'll help as best as we can
NOCODE or incorrect completion code
• Read more about why this may occur here: Participants are completing my study with 'NOCODE' or the wrong completion code
Please also remember that:
• If you're concerned that a rejected submission might have been made by a bot, then contact the support team immediately
• Prolific reserves the right to overturn invalid rejections in certain circumstances
For information on when you should request a study to be returned by a participant, see - Approvals, rejections, and returns
Need further help?
Click here to contact us