If a participant already has a submission in your study then it won't appear in their available studies list. 

If for some reason they need to revisit a study then:

First, make sure you can find their submission in "All submissions". Then, you can send them a direct link to your study via our internal messaging system. When they've completed the study you can use their original submission to reward them. 

On https://beta.prolific.ac you'll see all of the submissions together including "timed-out" ones when you go to "View submissions" for a study.

Did this answer your question?