1) If you look at the comments in your results file (lines starting with
#) you will see that the last column’s name is “Comments”: in your case, you get NULL in every line because there’s no comments to report. It’s not always the case: for example, if you use
log on a Scale element without
wait and the trial ends without the participant making any selection on the scale, you will get a line where that column reads “No selection happened”
2) One or multiple buffering events happening in the middle of a trial could indicate that the participant encountered difficulty playing back the audio, which could matter for some time sensitive tasks like primed lexical recognition. If that’s not relevant in your case, then you don’t have to log that information
3) I’m not sure what you are referring to. I tried opening your experiment multiple times, running as different groups, and the Sequence tab of the debugger always showed 25 trials. Maybe that used to happen in an earlier version of your project that had an extra value in the group column of the CSV table, or where there was a typo somewhere in the script that prevented part of the code from being evaluated?
4) This error message comes from the original Ibex: whenever an error prevents the script from filling the