Description of the problem:
I am new to Psychopy and trying to run a simple stroop task variant online.
The experiment consists of a trial run with 18 stimuli and the actual experiment, in which 40 stimuli are supposed to be selected from a list of 160 conditions defined in an excel file. To achieve this, I wrote the command “$random(40)*159” in the selected rows field of the loop dialogue in the builder.
This command is the only difference between the trial run and the actual experiment and it works perfectly when run offline.
When piloting the study through pavlovia though, the trial is completed just fine, but when the actual experiment is supposed to start, the following error message appears:
Unfortunately we encountered the following error:
- when importing condition: stim_ger.xlsx
- when selecting entries from an array
- unknown selection type: number
Try to run the experiment again. If the error persists, contact the experiment designer.
If I remove the command, the study runs perfectly fine again, but of course includes all 160 stimuli, which is not the purpose of the experiment.
I really hope that someone is able to help me with this. I have no experience with python whatsoever, but it is really important to get this study running online, because we cannot use lab-testing due to corona virus.
Many thanks in advance! Kind regards and stay healthy everyone!