Daily diary study

Hi! I’m about to run my first daily diary study on Prolific and I’m not quite sure how to set up the daily studies.
I’m interested in running a daily diary study for 10 working days. Participants are required to complete two surveys a day (lunch time and end of the work day). I understand that Prolific recommends setting up a separate study for each part of the longitudinal study, so I wanted to confirm if in this case that would be 20 different studies?
I was also wondering if there are any recommendations for how to set up completion codes - would these have to be changed with each separate study? If I keep the same codes, is there a risk for participant not taking the survey and just inserting the code?
I will be using Qualtrics as my survey platform.


Dear Irina

Welcome to the forum:-)

Good news. Ordinarily we are meant to create 20 studies one for each of the surveys in a longitudinal study, but Prolific makes an exception with diary studies.

Prolific suggests using only one study and a lot of bonus payments, or one study per day (ten studies) with a bonus payment.

Further details here

It seems to me that this introduces a grey area since researchers might claim that their study is a “diary study” and use this unpoliced method of running longitudinal or even screener plus propper study but that would be against the spirit of what Prolific is allowing.

I think it should be unlike that participants will use the same code for surveys that they have not done so I’d use the same code, which is the default (as far I as I can remember) for copied studies as your 10 (should you go down that path) are likely to be.


Hi Tim! Thank you so much for your fast reply and more importantly for clarifying my concerns - this was very useful!