Pavlovia - data sporadically not saved or logged

I am running 2 experiments using Pavlovia (which have the same basic structure, but different languages). They are generally working fine and data is recorded as expected, saved to .csv and with saving incomplete data switched on. We have so far collected data from about 100 participants with no issues.

However, about 5% of the time, a participant’s data is not saved. I know that they have completed the study as they screen share with a researcher while they are doing it, and they complete a number of other tasks outside Pavlovia which are all saved. The researchers do not report that these participants are doing anything different in the task.

I have read other topics in which there is a log but the csv is not present, or is blank. Here, in the “sessions” box I can see that the last session was, for example, this morning. However, there is no log of the participant and no .csv file.

Any ideas as to why this might be happening and/or how to solve it? The study has very specific criteria for participating so losing this data is quite unhelpful as it is hard to find additional participants! Thanks.

Are you 100% sure that the researcher sees the green barred “thank you for your patience “ message in these cases or might the participant occasionally close the Browser tab to move on before the message has been displayed?

I suppose that is possible, but since saving incomplete data is turned on, I (perhaps wrongly!) assumed that that wouldn’t be a problem?

Incomplete data saving doesn’t always work. It still needs the tab to stay open long enough for the data to be uploaded.

Yes “incomplete data saving” refers to saving data if your participant presses the “esc” key part way through - indicating they want to withdraw.

Incomplete data saving doesn’t avoid data loss caused by internet connection loss or computer shut down issues for example on your participants side.

Ok. That is frustrating but I understand. Thanks both!