More Pavlovia credits consumed than Prolific participants

Online experiments
1

I ran a small pilot of my PsychoPy experiment on Pavlovia to check whether data collection was working properly. I recruited 6 participants via Prolific and obtained 6 complete datasets, so the experiment seems to function normally. However, Pavlovia reports that 13 credits were consumed.

My assumption is that some participants may have started the experiment and refreshed the page, which may have launched the experiment multiple times.

I have three questions:

  1. Is refreshing or restarting the experiment the most likely reason why more credits were consumed than the number of participants who completed the study?

  2. Would you recommend enabling the option to save incomplete data to better diagnose such cases?

  3. How should researchers typically handle cases where participants refresh the experiment and start again (e.g., in terms of exclusion criteria)?

Thank you for your help!

2

Credits are only consumed when data is saved. If you are using credits then I would not recommend saving incomplete data, since this could cost credits if the page is refreshed.

3

Thanks a lot for your help, @wakecarter! Just to clarify: if credits are only consumed when data is saved, do you know why 13 credits might have been consumed if only 6 participants actually took the test? There are also only 6 saved datasets as of yesterday, when I ran the pilot.

4

Are you daisy chaining to another study or survey?

Where are you getting the value of 13? Do you have some credits reserved rather than consumed?

5

Thanks! I’m not daisy chaining to another study; the experiment only redirects participants back to Prolific at the end. In the dashboard it shows 14 credits consumed and 11 reserved. I initially had 300 credits and now have 283 remaining, which puzzles me since only 6 participants completed the pilot and I only see 6 saved datasets.

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6

Please could you add a screenshot for the number of sessions (bottom right) and PM me the URL to the study and I’ll ask @apitiot if he can look into it.

Also, please could you look at your credits tab and see if there’s any information about the 14 credits consumed? It should look like this:

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What I’m wondering about is double-counting. Do you have credits with identical consumption dates?

7

Hi @wakecarter. It seems the total number of credits is now being displayed correctly (294 instead of 283). The discrepancy was probably related to the 11 reserved credits. However, I’m still unsure why there were 11 reserved credits, since only 6 participants were recruited—do you have any idea what might cause that? I will send the PM you asked for. // EDIT: I tried to send you the PM you mentioned, but I couldn’t find an option to do so.

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8

If you refresh the browser tab during an experiment (including at the start) it will reserve a new credit.

It sounds like you don’t need me to look at anything, since you haven’t actually lost any credits.