Recognizing returning respondents
Why does recognition matter?
For the “Allow pausing and resuming survey completion” and “Prevent multiple submissions” features to work reliably, QUESTIONSTAR needs to be able to recognize returning respondents. Two mechanisms are used for this:
- Personalized links
- Cookies
1. Personalized links
When personalized links are used, a pseudonymized identification number (ID) is embedded directly into the survey link. Using this ID, QUESTIONSTAR can identify each respondent unambiguously — regardless of the device or browser used.
When such a link is reopened, the completion session is reliably recognized. Respondents can therefore resume their survey seamlessly or be prevented from completing it more than once.
Important:
Because the ID is contained directly in the link, the link must not be forwarded to other people. Otherwise, the recipient would not start their own new completion session, but would continue the session already begun by the sender.
The personalized links are generated in the “Personal Links” section of the “Distribute Survey” view. If you use the built-in mailer for the invitation, the links are created automatically and inserted into the emails (see the “Distributing surveys” section).
The identification parameters in the links are randomly generated, so that they allow no conclusions to be drawn about personal data. With the “Anonymize IDs” setting enabled, any link between a respondent and their answers is technically ruled out.
2. Cookies
When participation happens via a public survey link, no individual ID can be passed along. In this case, the first time the survey is opened, QUESTIONSTAR stores a cookie in the respondent’s browser — that is, a small text file with a randomly generated, unique identifier.
This identifier is anonymous, as it contains no personal information whatsoever.
When the questionnaire is opened again, QUESTIONSTAR checks whether the cookie is still present:
- Cookie present: Provided the “Allow pausing and resuming survey completion” setting is enabled, the completion session that was started is restored automatically.
- Cookie not present: The session cannot be recognized, and the questionnaire starts over — that is, a new session begins.
Note:
Recognition via cookie works only in the same browser on the same device on which the original session was started. If the browser cache is cleared, a different browser is used, or a private browsing session is used, the cookie cannot be read — and the session is not resumed.
Which method makes sense when?
- Personalized links are especially suited to non-anonymous surveys where it’s important to identify respondents unambiguously — for example, for personalized invitations, follow-up, or targeted reminders. They provide a high level of reliability in recognition, regardless of device or browser.
- Cookies are the right choice for anonymous surveys with public access where no personal data is to be processed. They allow recognition as long as the cookie is present — but only on the same device and in the same browser.
Unless the survey was opened via a personalized link, QUESTIONSTAR automatically switches to cookie-based recognition mode.