Prolific's prescreeners allow you to target participants that fit your desired experiment criteria. Prescreeners are free to use and you can have as many prescreeners added to a study as you wish. Note that the more specific your prescreening criteria, the narrower your potential subject pool.
Log into Prolific, select your study or create a new one, then scroll down to th "Audience" section. Under "Screening" select "Choose new screeners". For "Location", select "USA" or choose the apprioriate country if you are recruiting participants outside of the United States.
Under "Prescreen Participants", select "Add Screener" and choose your desired prescreening criteria from the available list. Note the "eligibile participants" counter at the top right of the window that shows you the total number of available participants.
A useful prescreening filter is the "Participation on Prolific" category where you can exclude participants from previous studies. This is typically used to prevent participant duplication across multiple studies that fall under the same project. Conversely, the "Include participants from previous studies" option can be used on longitudinal studies or multi-session studies that require participants to return after a set period of time.
