Bug Fix: Random with No Replacement

I am still having problems with the random with no replacement function. I follow the below steps listed in another post, but still can’t get the trial variable to reset reliably.

I end up going through the steps 10 times, eventually getting it to reset, but then only to have it stop randomizing the next time I try and use the program. Of course. I figure out that it isn’t randomizing mid-stream in my experiment when I am running subjects so it is a big problem.

Is there some other way to work around the bug or know for sure before I run my subjects that the randomize feature is working.


>The problem that your experiment was having was due to a bug in SuperLab. >SuperLab was not resetting the trial variable correctly. The bug happens in only >very specific situations, which is why no one had ran into it or reported it before.
>The bug fix will be part of the upcoming SuperLab 4.0.8 release, but meanwhile, >you can get around it in your experiment by following these steps:
>1. Change the variable to Sequential
>2. Save and re-open the experiment
>3. Change it back to Random With No Replacement

The list of steps mentioned was for a specific problem that a specific user was having. If this did not fix your problem the bug is not the cause of your issue. Therefore, it would be very helpful to know the exact details of the problem. For example, what’s not being randomized and what are you trying to reset? Are you having images overlap on the screen?

Do you mind posting your updated version of your experiment?

Problem w/ Random With No Replacement and Saving Trial Variable’s Value

Attached is a shortened version of the program that I am working with. After clearing my computer’s temp files, I stopped having crashes and still must reset occasionally, but still believe that randomization is not occurring properly.

It appears that there is some kind of problematic interaction with using the Variable Screen Location option for 3 Visual Stimuli that are Presented Simultaneously with the Screen Location of these 3 Visual Stimuli Determined Randomly with No Replacement using a Trial Variable that has 3 Levels/Locations.

Specifically, each of the three visual stimuli (e.g., Red, Brown, Yellow Squares) that are presented simultaneously (e.g., Trial 1 with Event 1, Event 2, Event 3) should appear at the 3 locations/levels (e.g., Right, Center, Left) roughly an equivalent amount of time (i.e., 0.33-0.33-0.33). But it seems that the order in which Locations/Levels are specified in the Trial Variable Tab (e.g., Right, Center, Left versus Center, Right, Left) affects the proportion such that it is skewed towards whatever location/level is listed first, then second, and then whatever is listed third.

With all that said, when I select save the variables value in the collected data file under the trial variable function, it saves only the location/level that was randomly without replacement set for Event 3, the final event in the Simultaneous Stimulus Presentation Series. Information about the location/level of Event 1 and Event 2 are not saved but instead show up in the data file with Event 3’s information. As is, there is way to know exactly where the program puts any stimulus other than that for Event 3.

Thanks and Please advise

Color MTS.zip (47 KB)

I have tried to replicate the problem, and indeed you are right about the output of the data file. We weren’t aware of it and I’ve just opened a bug report in our internal case tracking system.