View Issue Details
|ID||Project||Category||View Status||Date Submitted||Last Update|
|14965||Bug reports||Survey participants (Tokens)||public||2019-06-05 20:22||2020-08-07 06:00|
|Summary||14965: Group randomization issue|
I have a survey that has a set of question groups in the same randomization group.
Token persistence is enabled, and when a participant clicks on their email invitation and starts the survey, no problems of course.
But, if the participant doesn't complete the survey, and then returns at a later time, the survey loads with a blank question group.
As per the forum post:
Group randomization (at the group level) has always worked with no tokens for me. Its just when you mix in response persistence, a new session and a partially answered survey where they stopped in the middle of the randomized groups. It re-randomized the groups putting an unanswered mandatory question before the last question answered, then tried to send you back to the last question answered which resulted in the a group loading with error classes and hidden questions, unable to proceed forwards.
|Tags||No tags attached.|
|Complete LimeSurvey version number (& build)||3.17.4 Build 190529|
|I will donate to the project if issue is resolved||No|
|Database & DB-Version||359|
|Server OS (if known)|
|Webserver software & version (if known)|
@ollehar : related to SEED ?
Will have a look today.
limesurvey_survey_959263.lss (23,595 bytes)
I need clearer instructions on how to reproduce. This is what I did:
Can't see any different in group randomization. Also tried with clicking "Resume later".
I was just able to replicate on the first attempt on the https://demo.limesurvey.org site which looks to be running Version 3.17.3. This issue has existed for as long as I can remember and no one seems to know about it so I think we can safely assume it still exists in 3.17.5.
See attached screenshot for what you will see when experiencing the bug.
If you don't see it on the first time, just immediately close the window and re-enter in a new private window. Sooner or later you will see it.
Now chances are, no one will be entering the survey like above. But its no different than starting a survey on your phone then completing on your desktop later. Its just the easiest way to replicate.
@Bigred01 : you can use demo for checking, but it reset all night.
Can you send the related lss please ?
I used the one posted above by ollehar. I believe it’s the original one I posted to the forums 10 months ago.
OK :) Great :)
Shuodldn't be using newtest=Y all time?
The issue is more than that though. When you come in with a clean session after already answering some questions previously, the groups would be re-randomized and it might put an unanswered mandatory group/question before the group it starts you at. It then renders a page with all questions hidden due to relevance error classes and you cannot proceed. My quick hack was to store the group order in a db table using the sid & token as the primary key and use that on entry instead of setting a random order again. I cant remember where in the code i did that now, that was a while ago. That paired with newtest=Y appeared to work but its not a real solution, just a quick hack to get a survey out.
@ollehar : seed must be used to have same radomization for same token ? No ?
I wouldn't rely on the seed to get reproducible numbers.
Besides what it says here (https://www.php.net/manual/en/function.srand.php#16513) you can;t controll that every time that you rturn, the same number of random numbers will be retrieved. You "may" guarantee the sequence is the same. But can you guarantee that there will be no extra random number request in between the sequence?
One of the problems should have got solved by using the newTest parameter on the url.
Having a constant randomness is another issue and is because random sequences are not saved.
I will leave @cdorin review what is the suggested next steps.
It does prevent people from completing the survey though. How i found it in the first place was when we started to receive a series of complaint emails. Group randomization is essentially useless when you have token based response persistence on and someone doesn't complete the survey in a single sitting. There is a very good chance the next time they enter they will encounter this.
I understand you mean.
|2019-06-05 20:22||blocka||New Issue|
|2019-06-06 09:07||DenisChenu||Note Added: 52313|
|2019-06-06 10:14||ollehar||Note Added: 52314|
|2019-06-06 10:14||ollehar||Assigned To||=> ollehar|
|2019-06-06 10:14||ollehar||Status||new => assigned|
|2019-06-06 10:50||ollehar||File Added: limesurvey_survey_959263.lss|
|2019-06-06 11:04||ollehar||Status||assigned => feedback|
|2019-06-06 11:04||ollehar||Note Added: 52316|
|2019-06-06 11:04||ollehar||Note Added: 52317|
|2019-07-11 00:39||Bigred01||File Added: groupRandBug.JPG|
|2019-07-11 00:39||Bigred01||File Added: groupRandBugQuestionClasses.JPG|
|2019-07-11 00:39||Bigred01||Note Added: 52821|
|2019-07-11 07:46||DenisChenu||Note Added: 52823|
|2019-07-11 07:54||Bigred01||Note Added: 52824|
|2019-07-11 08:04||DenisChenu||Note Added: 52825|
|2019-07-11 10:29||ollehar||Status||feedback => assigned|
|2020-08-05 17:24||cdorin||Priority||none => normal|
|2020-08-05 17:24||cdorin||Status||assigned => acknowledged|
|2020-08-06 17:51||gabrieljenik||Note Added: 59349|
|2020-08-06 17:59||Bigred01||Note Added: 59352|
|2020-08-06 18:51||DenisChenu||Note Added: 59353|
|2020-08-06 22:00||gabrieljenik||Note Added: 59356|
|2020-08-06 23:13||Bigred01||Note Added: 59362|
|2020-08-07 06:00||gabrieljenik||Note Added: 59364|