It is a question:
Data files have the following format:
Could you explain what the last part of the name (i.e. 40.45.492) is constituted of and can it be used to track the experiment end up to a second? What happens when two participants complete it at almost the same time? Can there be lags?
I am pretty sure that you are correct that they correspond to seconds and in the rare situation of simultaneous data submission you shouldn’t be too worries about lags.
paging JS folk to check my understanding @thomas_pronk
Many thanks, Becca. I just have a few participants with the same hours and minutes (say, 11:45) but different seconds (presumably) and I need to distinguish the order of submission.
I think the last part is even milliseconds. So for example, “40.45.492” means:
- 40 minutes
- 45 seconds
- 492 milliseconds
Thank you. The problem us I dont understand how the time stamp is prepared. Right after the last page, participants were redirected to a survey page and the survey start never corresponds to the file name i. E. this time stamp, while the file creation time (in the dowloaded folder) does, so I know it worked and can relate the experiment and the survey together, but not when using the file name.
I’m not 100% sure about this, but I could figure it out if you like. Here is my hunch: the timestamp used to for the filename is based on the time as measured on the computer of your participant. The timestamp for the file creation is based on the time as measured on our server.
Now in general, using timestamps to match participants is a bit tricky. I strongly recommend using some unique ID
Yeahh, we figured it out too late. Lesson learnd and now using id.
It makes sense what you say, but in most cases there is a discrepancy in these time stamps in almost an hour. How come?
I’d guess a time difference between the timezone of the computers of your participants and the timezone of the server
Then it should be an hour, but sometimes its 15 min, sometimes 40…very random…
Sorry for asking too many questions. I am wondering if two participants have the same server time in minutes and hours but apparantly differ in seconds, can I be sure that the order in the folder on pavlovia is correct? Is there a way to see the seconds on the server time? Many thanks!
Well, then I can’t explain it, I’m afraid
About you question on order. The order would be based on the moment the file gets saved on the server. Generally, that would correspond to the moment the participant completes the experiment, however… imagine participant A completing it just after participant B, but A has a faster internet connection, then A’s data could be stored before that of B.
About the seconds on server time. I don’t know, but I could ask. Beware though, you’d probably need to use relatively more complicated tools, like the git command line interface.