We ask that researchers do not screen participants out in their studies. Instead, you can apply Prolific's prescreeners to your survey, which will mean only eligible participants can see and access your study.
The full eligibility criteria for your study must be applied using prescreening, so that all participants who are sent to your study can complete it and receive the reward. If the criteria wasn't applied to your prescreening, you cannot reject participants or exit them from your survey if they do not meet the criteria you're looking for (see step 4 here).
Here is an example to see what we mean:
I am a researcher who wants to conduct a survey on people who own dogs but I forgot to apply the prescreener for dog owners. This means that I cannot reject or screen out participants who do not fit this criteria.
It is very frustrating for participants to get unexpectedly kicked out of studies, and our platform has been designed to help you recruit only the specific sample that you require for your study. Any participants inappropriately screened out of a study should not have their submission rejected, and will require payment.
What if the prescreener I need doesn't exist?
If you want to recruit a niche demographic that you can't obtain using our existing prescreening filters, you will have to make a custom prescreener. Please refer to the recruiting a custom sample for a more detailed explanation.
Here is an example of how to use custom prescreening:
I'm a researcher who only wants to recruit individuals whose favourite flavour of ice cream is chocolate. However, I could not simply ****publish my study, ask the question in my survey, and reject any participants who respond that their favourite flavour is vanilla or strawberry (or exit them from the survey).
As there is no existing screener related to participants' favourite ice cream flavours, I would instead have to run an initial screening study which contains the question:
"What is your favourite flavour of ice cream? Vanilla, Chocolate, Strawberry...etc."
Once I've collected the data from this initial study, I will have a list of Prolific IDs that match my desired screening criteria (i.e. any participants whose response is "Chocolate"), and can invite them to my main study using a Custom Allowlist.
Can I validate my prescreeners?
Yes, we recommend that you validate your prescreeners by asking the prescreening question again in your survey. This validation question should be at the very beginning of your study and must be worded exactly as it appears on Prolific. This will allow you to confirm that participants’ prescreening responses are accurate and up-to-date, so you can be sure you are obtaining your desired sample.
If a participant's response doesn't match their prescreening answer, you can redirect them to a separate end of survey page with the following message:
“You are ineligible for this study as you have provided information which is inconsistent with your Prolific prescreening responses. Please return your submission on Prolific by selecting the 'Stop without completing' button.”
Please note, that this typically is the only circumstances where we allow screening within a study.