There are several methods to avoiding repeat participants to studies, depending on how you're doing recruitment.
Recruiting with Outset: how to avoid repeat participants
Sometimes, your team may be setting up several similar studies, and you want to avoid having participants repeat different versions of the study. For example, you could have a study recruiting adults with kids to review concept A, and another study recruiting adults with kids to review concept B.
If you are recruiting with our integrated panel partners (Prolific and User Interviews), we have methods to prevent participants from repeating the study.
Participants who complete a specific study cannot repeat that same study
Participants who complete study A within a project cannot complete study B within that same project. Note that there is not an option to prevent duplicate participants across different projects. Read more here for a reminder on the differences between studies and projects.
Recruiting externally: how to avoid repeat participants
If you're recruiting participants on your own and want to make sure people can't retake the screener after being screened out, Outset supports unique interview links that block repeat attempts. This helps ensure your data stays clean and that disqualified participants don’t try to re-enter the study.
1. How the unique participant links work
When you include a participant ID in your interview URL using the variable name outset_survey_uid, the system will generate a unique link for that participant. Once the link is used—whether the participant is screened out or completes the interview—any further attempts to use it will be blocked. Instead of seeing the screener again, the participant will get a message that they are ineligible for the study.
This functionality only applies when you're using the "Recruit on my own" option.
2. How to create unique participant links
Start by copying your interview's shareable link from the "Recruit on my own" tab. It will look something like this:
https://api.outset.ai/interviews/public-surveys/abc123/start/
To turn this into a unique participant link, just append a participant ID like this using the embedded variable name "outset_survey_uid":
https://api.outset.ai/interviews/public-surveys/abc123/start/?outset_survey_uid=12345
In this case, 12345 is the unique ID for one participant. You can distribute different versions of this link to different participants, each with a different ID. Be sure to:
Replace
abc123with your actual interview IDUse a unique ID for each participant
Use the exact variable name:
outset_survey_uid
You can generate and send these links using whatever email or CRM tools you prefer.
3. What participants see if they try to reuse a link
If someone tries to reuse their unique link after being screened out or completing an interview, they’ll see a message saying they are ineligible to participate. This message is standard and not customizable.
4. How to check if a link has already been used
If you want to check which participant IDs have already completed the screener or been screened out, you can do this by looking at the metadata column on the interview results page. This column will include the outset_survey_uid value that was passed in through the link, allowing you to match responses to individual participants.
5. When to use this feature
This system is especially useful for studies where you're handling recruitment yourself and want to prevent duplicate entries. If you're using the general shareable link (without participant IDs), this protection won't apply. So if repeat attempts are a concern, we recommend using unique links with outset_survey_uid for each participant.
Hope this helps! If you have any further questions, please reach out to our team at [email protected] or via chat.