Hey @MargaretW, just wanting to clarify on your original question - are you talking about identifying respondents from the original survey or the follow up survey?
If you’re wanting to identify them in both, you could use @brookel’s suggestion of a query string on the end of the anonymous link for the second survey. This would mean in the first survey, you capture their email address as a question, and also save it as embedded data. Then in the 28 day delayed email trigger workflow, you would build the anonymous link to include the query string with the embedded data email field as piped text in the email body. Then when they click on that link to complete the second survey, the query string would pipe in their email address so you can capture it as embedded data. You would then be able to match the two responses (and anything else the person has done with the same email address).
The other option you might consider is adding respondents to a list or directory as part of the workflow when they complete the first survey. You can then set up your list to trigger an email to new members after the 28 days. This would then generate a personalised email link to them and you would have the information they already populated (e.g. if you wanted to capture demographics in your first survey, you would have that saved in the directory for when they responded the next time). There’s some more information on this process here https://www.qualtrics.com/support/survey-platform/actions-module/xm-directory-task/#SendingEmails
Hope this helps with your survey plans!
