Random assignment to different survey versions?

I would like to assign participants randomly (or round-robin/alternating) to two different versions of the same basic Google Forms survey, making sure that no participant does both versions. Having assignment to different experimental conditions seems like something a lot of people would want to do, but after some searching I’m unable to find any information on how to do this within Prolific.

I’m aware that one can do this within the survey itself if the survey is in Qualtrics, but I’m collaborating with someone using Google Forms and it would be a big extra step to change platforms.

Any suggestions would be much appreciated, thanks!

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Hello @PSR, and welcome on board! :boom:

As you correctly said, randomisation can already be done via some external survey platforms like Qualtrics or oTree. However Prolific doesn’t (yet) have survey functionality and cannot manage randomisation itself.

One possibility, however, is to create two different studies, one for each treatment condition you have. You have two options to exclude participants who were already engaged in the first condition from your second condition: either you use the ‘Custom Blocklist’ prescreener or the ‘Exclude participants from previous studies’ one (you can read more about them here).

Of course you should check with the appropriate statistical tests whether randomisation worked as expected (so that you have homogeneous groups by age, gender, etc.).

Hope this helps!

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Hi PSR and Welcome :slight_smile:

Veronica has covered all the bases but, one other thing - the custom black list is created automatically if you use the top right menu and Copy Study, so those that took the first study will not be able to take its copy.

Then just paste the link to the second version of the study in the copy.

I use Google forms too and that is what I do.