How to make sure each list will be used only once when automatically import new Conditions list for each person?

Hi everyone,
I would like to run an experiment online, where participants need to see a set of pictures and answer some questions. What is key here is the order of the stimuli - the conditions to be met are quite complicated. In the offline version, I used unique lists of conditions, and I manually imported them as Excel files - new Excel for each new person. They were previously created by the Matlab script - as I am able to do it in Matlab, but I am new to Python and use mostly Builder with some copy-paste addition as a “code” custom elements. Each list was used only once.
But now I need to re-run the experiment online on a larger group. I already found a way to import the new list each time experiment is started on the forum: Import different lists on Psychopy - and I hope I will be able to implement it. But how to make sure each list will be used only once? Considering the fact, that study will be online and each person will start independently, so it is theoretically possible that one participant haven’t finished session and the new one already starts a different session?

Hello febe.beata

would it be a solution to tie the list to the participant-number? So, participants 1 gets list 1, participant 2 list 2 aso. You need to assign the participant number by some other piece of software, qualtrics, formr, vespr to get unique numbers.

Add this in a code-component in the Begin experiment tab.

testList = "List" + (expInfo['participant']) +".xlsx"

Then, in the loop of the relevant trial-component, specific Conditions with $testList.

Best wishes Jens

You can use the VESPR Study Portal to do this.

If more participants start at the same time than there are groups, then the assignment is made without knowledge of who will abandon the experiment, but to cope with that eventuality would require a fortune teller.

Best wishes,