How to pass an email address or other identifier into (or out of) your study

Note: You'll need a paid subscription in order to use this feature.

Sometimes, you already have the participant's name, or email address, or customer number when it's time for them to take a study, and it's what you want them to be identified by when they do your study. There are plenty of reasons for this:

  • You've already asked for it in a separate screener
  • They're already logged into the system you're administering the study from
  • You're redirecting them from one Optimal Workshop study to another

In any case, you don't want them having to enter their details again in order to do the study.

How to pass an identifier (name, email, etc) into your study

Optimal Workshop study URLs take the form:

To pass in your own identifier for the participant, add the query parameter i=XXXXX to the end of the study URL. So, in the case of a Treejack study, it might look like this:

You also need to set the Participant Identifier in the Questionnaire tab to 'Other' (which you can label for your reference). If you leave it set to 'Anonymous', our system will allocate an ID number to the participant that will override your identifier. 

Redirecting with the same identifier once the participant has completed

On the 'Messages' tab of the study setup page, below the Thank You message is a text field for entering a post-study redirect. To insert whatever was passed in at the beginning of the study into the URL, use the text [ENTRY] as part of the redirect.

As an example, if you enter this url into the post-study redirect field:[ENTRY]

When your study is completed, assuming the participant was identified themselves as "" when they started the study, they would be redirected to

Note that when you preview your study, this redirect won't appear to work correctly, since the preview doesn't create a participant record in our database. To confirm that the redirect works correctly, you'll need to "launch" your study.