Issues on experiments using MTurk integration of SoPHIE

[Junhui Wu]

Dear all,

       Does anyone of you have conducted experiments using the MTurk integration of SoPHIE? I have an experiment designed with random matching (16 participants at the same time). It happens that when all the 16 assignments have been taken, there still comes  a warning message in the session log saying "MTurk: Different Worker logged in for an existing assignment". In what situation can this happen?

       Another question is, in the session administration page, "Participants" under the "Mturk" button shows that some of the participants do not have an assignment ID. Does that mean that these participants return the HIT or drop out immediately after they accept the HIT?

   

      It seems really difficult to control this kind of synchronized experiments on Mturk. If someone drops out, other participants who are not able to continue complain a lot, how do you usually deal with this issue? I tried to terminate (finish) the session when this happens, but participants' page becomes the login page afterwards, which causes them to send me message asking about the participant code. How to deal with this problem?

      I am looking forward to hearing any of your comments and suggestions! Please feel free to add any tips that you might have if you do have experience with this! Thank you very much for sharing! :-)