Hi all,
I’m planning to run a within-subject crossover study in LimeSurvey. Each participant will complete two sessions one week apart (T0–T3 in each). In session 1, participants are randomized to condition A or B after T1, and I need to see (they need to tell me) the result immediately because I apply the treatment myself. In session 2, they get the other condition, so the system has to know what they received in session 1. The survey is open (no tokens), participants enter a self-generated code, and I must not be able to link responses to persons.

1. How can I randomize once after T1 and show the result right away?
2. How can the system remember the condition for session 2, one week later, when many other participants are using the same survey link in between?
3. How can participants continue in session 2 and automatically get the other condition?
4. Is “save and resume later” suitable for this without storing email addresses?
5. Would two separate surveys be more robust for this design?

Not sure if I fully understand your needs but what about this?

Two surveys:

In survey 1:
Say they got option B - they now see this end message

Here is your link to take part in the second survey which will become active on (Date):

Code:

https://yourplatform.com/123456?Condition={Condition}

You could also pass the user generated ID here, so you have a link between survey 1 & survey 2 per respondent

In survey 2, hidden short free question at the start: Condition. This gets prefilled with the condition shown in survey 1. You can now show or hide questions based on this. So if respondent link is Condition B -> show questions related to Condition A for second survey.

The difficult part is that respondents will have to save your link somewhere which isn't ideal.