Description of the problem:
I’ve had a number of participants on Prolific message me with the same issue - I wonder if it’s becasue of a few concurrent users? Any guidance is really appreciated!
I should say this doesn’t happen for all participants - but a reasonable number nonetheless
Unfortunately we encountered the following error:
when getting the name of a group, using a counterbalanced design with key: [“counterbalance”,“@designer”,“@experiment”]
unable to access the record for the given key: either it does not exist, or it is locked, possibly by another experiment session
Try to run the experiment again. If the error persists, contact the experiment designer.
I have multiple participants on Prolific messaging me with this error code: "Unfortunately we encountered the following error:
when getting the name of a group, using a counterbalanced design with key: [“counterbalance”,“@designer”,“@experiment”]
unable to access the record for the given key: either it does not exist, or it is locked, possibly by another experiment session
Try to run the experiment again. If the error persists, contact the experiment designer"
I’ve unlocked the experiment on the shelf only to find it locks itself again, run it locked, run it unlocked and there doesn’t seem to be any reason why it sometimes works for some participants (about 4) and not for others (over 20 aborted/experienced this error).
Does anyone have any experience with these errors? I’m aware there’s probably done wrong somewhere in the setup but can’t seem to find a guide on this so help would be much appreciated, especially as I’m running out of time.
Hi. I’m afraid that it looks like the counterbalance routine can’t yet cope with simultaneous starting participants. You could use the VESPR Study Portal instead, which uses a different method.
Let me know when you’ve created a account and I’ll add a free licence for you (needed for random allocation to groups using a variable called group. You can decide afterwards if it was useful enough to want to pay for.
The portal is designed to host the PI sheet but you can set it to launch directly.
That is very kind, thank you! I’m just trying to navigate your site now, so hopefully it will work! Just let me know what details I need to provide!
As an addition, I tried limiting number of respondents on prolific to 1 at a time and the same error occured, so might not just be simultaneous starts?
For the record, the issue here is that the algorithm of the counterbalance routine is not meant to deal with simultaneously starting participants where each slot is 1, with many repeats, instead of having larger slots with less repeats.
We are looking into the matter on our end, and will have a variety of algorithms on offer in the coming weeks.
