Missing Data Files (using PsychoPy)

Online experiments Pavlovia Surveys
1

I ran 334 participants through Prolific, but only 275 data files were available from Pavlovia, and of those, only 268 contained usable data (some were completely blank). As a result, I am unable to use the data from 66 participants.

I created the task using PsychoPy. After completing the task on Pavlovia, participants were redirected to a Qualtrics form to fill out demographic information. I have records confirming that all 334 participants filled out the demographic form, suggesting they completed the task on Pavlovia.

Initially, I thought the issue might be related to too many participants running the task simultaneously, but I don’t believe that is the case. Below is a histogram showing the start times of participants:

StartDate_Histogram
StartDate_Histogram1200×800 21.5 KB

Upon reviewing the data files, it seems that data might be getting lost when multiple participants begin the task at the same time. Could this be the cause of the issue?

Any suggestions or insights would be greatly appreciated.

2

Hi @Kara,

I am not a PsychoPy or Pavlovia developer so I won’t have the most complete understanding of what might be causing your data loss. But I have a couple questions that might help.

  1. In your Pavlovia dashboard for this specific experiment, is Save incomplete results checked? On the experiment page, it is a little dashboard that looks like this:

    image
    image211×262 13.1 KB

  2. In your PsychoPy experiment settings, what is the Incomplete URL set to?

    image
    image343×221 9.88 KB

    If Save incomplete results is unchecked, and the Incomplete URL is your link to Qualtrics, then you could end up in a situation where participants ended the study early (and their results are not saved because they are “incomplete”) but are able to complete the Qualtrics survey. Possible Solution: Check the Save incomplete results box, and/or change the Incomplete URL to be something that is not your Qualtrics data (best solution depends on if you want incomplete data or not)

  3. What version of PsychoPy are you using? (some PsychoPy versions had a bug that would come up during daisy-chaining)

  4. What is the name format of your participant data files? Could you share an example of the data file name of one that saved successfully? By default it is typically something like this (found in Properties(the gear button) > Data > Data filename):

u'data/%s_%s_%s' % (expInfo['participant'], expName, expInfo['date'])

The answers to the 4 questions above might help narrow down the cause of the data loss. This older thread also talks about other causes of data loss and how to recover the data (in some cases).
-shabkr