Hi all~
My experiment is cognitive bias modification.
My experiment has two blocks.
One is preliminary with five stimuli and the other is main trial with 45 stimuli
So I wanna randomly select five stimuli for preliminary among the total(45 stimuli).
And, of course, the total is used in the main trial.
then, what should i do?
This is my builder, and preliminary
I didn’t know how to do it, so I made two Excel files seperately.
And, in the preliminary trial file, I just selected five stimuli one by one each time by generating random numbers on the Excel.
But it’s soooo uncomfortable
Help me please.
Each repetition of the loop, Psychopy will add 1 to the variable thisTrial, so to choose 5 trials at random and then end the loop you just have to create a Code component with this in the “End Routine” tab:
if thisTrial >= 5:
break
break is a command in Python which ends the loop it’s in - and code from this tab is put within the trial loop, so that’s the loop it will break. So this code is essentially saying “after 5 trials, end the trial loop”
thank you sooomuchTParsons
but yet i can’t understand …
i put '44 stimuli(now 44 are total.) ’ used in main trial in condition
and I check ‘is trial’ and I put 1 in nResp $
like this
You’re getting that error because pretrials is the name of the loop itself, not the number of the trial you’re on. The loop itself doesn’t have a numeric value, so when you ask Python “is this greater than 5?” it doesn’t know how to answer (it’s like asking “is a chair less than or greater than 5?”). You need to compare it to thisTrial, or pretrials.thisTrialN, as this will be a number. The rest looks fine though!
sorry
TParsons
I have another problem.
I have to syn on pavlovia with changed experiment for online experiment
but The Pavlovia link is suddenly not working with the code you mentioned.
Oh, and since i did it the way you did it, there were six stimuli, so I modified it like this.
