Questionnaires of one project mixed up

Question

My project contains 4 questionnaires - 2 experimental and 2 control groups.

The issue is that some control group participants somehow got the questionnaire from the experimental group and vice versa (I can judge this based on screenshots provided by participants). Why did this happen and how to identify now which respondents got which exact questionnaire?

Answer 1

Why did this happen and how to identify now which respondents got which exact questionnaire?

Sounds like you messed up the random generator or PHP code that were responsible for the randomization. However, if you had different questionnaires, the variable QUESTNNR should be quite concise. So start with checking your download.

Please also follow the debug information throughout several test cases, and check the codes stored in your random generator and what you see. You can also post your PHP code here to give us a look.