Counterbalancing in OSWeb/JATOS using lists

amlema

Hi!

I have designed an experiment in OpenSesame which uses 8 different lists, as defined in a loop item. I want to upload this experiment to JATOS in order to send it out to participants, so I have tried to follow the instructions on counterbalancing as documented here: https://osdoc.cogsci.nl/4.0/manual/counterbalancing/ , but this does not work for me. Is the only way to do this to make the experiment 8 times under the sequence item? For a desktop experiment, this was an easy fix with a simple line of Python code, but using JATOS and JavaScript, I am majorly struggling. This is my first time designing and running an experiment using OSWeb and JATOS, so I am sorry if this is just an obvious fix.

Thank you so much in advance - I have been stuck on this for a good while now.

Best, Amber

sebastiaan

Hi @amlema ,

The thing that makes it tricky to do counterbalancing in OSWeb is that you have to use the batch-session data to keep track of which participant is assigned to which list. (To avoid ending up with more participants for list 1 then list 2, say.) The documentation shows how to implement this, with the slight difference that is uses a condition variable with four levels, rather than a list variable with eight levels. I would first focus on getting this part to work.

Once you have set up your experiment such that you have a list variable that is retrieved from the JATOS batch-session data, you can implement the rest of the counterbalancing logic more-or-less as you would on the desktop.

Based on your description, this is all I can say. If you get stuck, please provide more details of what you are trying to do, what you have done exactly, and why this doesn't work as expected!

— Sebastiaan