PHP sessions now destroys sessions on a participant completing the study. This should ensure people can't go back and change answers / resubmit data once they've finished.
PHP sessions now destroys sessions on a participant completing the study.
This should ensure people can't go back and change answers / resubmit data once they've finished.

uoscompsci/PRISONER,uoscompsci/PRISONER,uoscompsci/PRISONER