PsychoPy version 1.85.4
Hello everyone, I’m creating an experiment in which a set of stimuli (images) will be presented to the participants, and we’ll record their responses using the keyboard.
I would like to (psuedo)randomize the stimuli according to one parameter (in the same Excel sheet). This parameter, “Congruency”, has 3 levels, “congruent”, “incongruent”, and “neutral”, and I would like 1/3 of the stimuli presented to be from each level. There are differing amounts of congruent, incongruent, and neutral trials, so I am unable to use all of the stimuli and achieve a 1:1:1 balance, and even if there was an even amount, I do not plan on using all of the stimuli for each participant, so there is no way to ensure balance.
Additionally, I have considered making a different conditions file for each level, however, this does not work because I want individuals to have an equal probability of seeing a “congruent”, “incongruent”, and “neutral” stimuli each trial, NOT all “congruent” trials in succession in followed by all “incongruent” trials in succession.
I’d also prefer NOT to just remove stimuli of a certain condition until a 1:1:1 balance is achieved, and then import the conditions file.
If I sort the excel sheet alphabetically, is there a way to specify that I would like 30 stimuli from rows 1-50, 30 stimuli from 51-150, and 30 stimuli from rows 151-200, while also making sure that all of the stimuli are randomized between?
Because I plan on running this experiment online, there are certain features that are not supported: like code components. With that in mind, I’d prefer to use builder features that are supported online (and no code, as I do not have coding experience).
Any ideas would be greatly appreciated.