I'm running a survey (Limesurvey version 2.62.2) with an internet panel. Respondents are redirected from the panel provider, and sent back to the panel provider after completing the survey. For 16 out of 600 respondents approx 7 URL parameters are not saved. Instead, a refurl is saved without the parameters included. This refurl is effectively survey url, but stripped from all URL parameters; it also lacks the language URL parameter. This refurl is not saved for any of other respondents. These 16 respondents completed the survey within reasonable time; it seems if they did not leave the survey in the meantime, judging by the startdate and submitdate.

I was thinking that a browser plugin could strip a URL; I've tested two now, without being able to replicate the issue. These plugins usually strip more obvious parameters like lng, lat, utmsource, but not arbitrary parameters.

Does anybody have experience with this issue? Thanks!

The existence of or lack of an referrer is not giving a strong indication for the missing URL values
The URL parameter transfer is completely independent from transmitting the referrer.

You might ask your panel provider to pinpoint these respondents and check if they reported issues with you survey.

In every survey big enough you will find some respondents with issues. Sometimes it is a browser plugin (you won't be able to reproduce easily without knowing the respondents setup). Sometimes it is a proxy / gateway.
If you have seven parameters you might have a very long URL which can cause trouble in some constellations.

I wouldn't invest to much time, but add a hidden question to grab browserinfos via javascript for future surveys. That sometimes can give you a hint where to look for.

Thanks for your reply. I'll store the browser info in future survey.

I spent some more time investigating the issue and replayed some possible scenarios.

My current hypothesis is that these respondents opted for 'Exit and clear survey', changed their mind, and pressed 'Restart this survey'. Once pressing 'Exit and clear survey' their responses (and IP-addresses) are removed from the responses table, and they start with a blank slate, and are referred to the survey by the survey itself. This gives results in the refurl being the survey url. Also there are no double IP entries in the response table. I might remove, or hide, the option 'Exit and clear survey' from my template for panel surveys.

michaelve wrote: …
My current hypothesis is that these respondents opted for 'Exit and clear survey', changed their mind, and pressed 'Restart this survey'. Once pressing 'Exit and clear survey' their responses (and IP-addresses) are removed from the responses table, and they start with a blank slate, and are referred to the survey by the survey itself. This gives results in the refurl being the survey url. …

Can you control this behaviour ? I think it's a bug and must be fixed.

Best is to control with different type of URL Fields : www.limesurvey.org/manual/URL_fields#Places_to_use_URL_fields

Thanks for following up.

I'm not sure whether this counts as a bug, the pop-up message is rather clear: would you like to delete your responses. This indeed happens.

On the subsequent page it is possible to 'Restart the survey'. However, for the panel provider these respondents should be routed back to them with a message that the respondents did not complete the survey. Also, it might be wishful to still store some of the session details, just to know that the survey exiting occurred.

We (I) can fix it in a plugin, not the question here : because i thik the needed behaviour by core is to keep URL get params (anyone), we keep token, i think we must keep other one.