If your participants are being supplied by a participant panel, you'll want to be able to identify that the participants have actually completed the study correctly. This is generally achieved by passing a unique identifier for each participant generated by the panel into the study, and then back out again at the end.
Passing an identifying string into your study
Optimal Workshop study URLs take the form:
To pass in an identifier from the panel, add the query parameter token=XXXXX to the end of the study URL. So, in the case of a Treejack study, it might look like this:
In this case, the 12345 needs to be provided by your panel.
Redirecting back to the panel once the participant has completed
On the "Messages & instructions" tab of the study setup page, below the Thank You message is a text field for entering a post-study redirect. To insert the token that was passed in at the beginning of the study, use the text [ID] as part of the redirect.
As an example, if you enter this URL into the post-study redirect field:
When your study is completed, assuming the participant was given the identifier "12345" by the panel, they would be redirected to
We don't have any way of turning away participants who fit a certain demographic once a certain number of results for that demographic have already been collected.