You can add a hidden question to your survey to capture where the respondents were just prior to entering the survey. For example, if you posted the survey link on multiple sites such as
www.youtube.com, you could track the full URL of the site respondents visited before starting the survey.
To capture the referer URL, add the vReferer question at the top of your survey right after the
<text label="vReferer" size="40" optional="0" where="execute"> <title>Capture Referer</title> <exec> vReferer.val = gv.request.getFirstHeader('referer') </exec> </text>
This codes creates the first hidden question in your survey. After your survey has collected data, the answer to this question provides you with the referer URL.