Empty csv files when using the WebApp for counterbalancing

URL of experiment:


Description of the problem:

Hey guys,
I get data back from my experiment when it’s used locally and also online via Pavlovia. Now that I needed to insert the WebApp that assignes participant numbers for counterbalancing issues, each time I download the results from Pavlovia it gives me empty csv files for all the participants :frowning: to test if it might be a problem on their end, I also completed the experiment, but there is also only an empty file.

Also, I realized that no participant numbers were actually assigned by the App…in the Data it only says “PARTICIPANT…”

I would really, really appreciate help to fix this problem!


Do you have participant as one of your expInfo variables? If you deleted it then your experiment won’t read the value sent by my app.

Thanks for your reply!

Yes, my experiment does have ‘participant’ as one of the variables, and it will be used in the data analysis later on, so I didn’t delete it.

Clicking on the app link gives a not found error, so I’m assuming you’ve made the experiment inactive. However, the link is if the form https://run.pavlovia.org/Lealexandra/new_prototype_induction_exp/?participant=20&id=&session=&researcher= which as you can see is sending a value for participant.

Thank you for looking that up! Yes, I did de-activate the experiment in the meantime and “solved” the problem in a quite inelegant way (creating a new experiment folder on my desktop, copying the old experiment and renaming it to create a new project on Pavlovia).

I remember that in the link it used to show that participants were counted, as you correctly mention above. Still, I don’t understand why the corresponding data didn’t show up in my data folder. Could it possibly be that all participants did exit the experiment without waiting for the final dialogue box to click “ok” for data transfer?

You were getting data files so as far as I can see the only possible error is you not having “participant” at an expInfo variable. I can check what’s going on if you send me your new VESPR link just by viewing the expInfo box with and without going via my link.

Actually, since I created a new project on Pavlovia (but without changes compared to the old experiment) everything works just perfectly with the VESPR link. I checked the csv files and it didn’t happen again that they were empty. The link is:

I still do not understand though why it didn’t work out with the ‘old’ experiment, as the settings were exactly the same.

Thank you very much for looking it up! :slight_smile:

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