Create different counterbalances between subjects

KimS

Hi,

I am new to OpenSesame this afternoon (and I have very little experience with Python) and am a bit confused about how to counterbalance. What I want to do is have 4 different stimuli sets with each participant only seeing 1 version. My actual experiment is a little complicated (there will be multiple loops for each version) so it's probably best to give a more simplified experiment so let's say I want participants to either see a set of tasks based around either a dog, a cat, a horse or a dolphin. Participant one should only see words relating to dogs, participant two should only see words relating to cats, etc.

Is it the case that I would need to create say a mainloop as in the Chris Longmore video example? Within this would need to be one loop for each experiment version (dog, cat, horse, dolphin) which would then each have its only 'sub' loops? I would then need some form of inline code to determine which version is run - would that simple be the case of something like:

if self.get('subject_nr')%4 ==1:

b1=0

if self.get('subject_nr')%4 ==2:

b2=0

if self.get('subject_nr')%4 ==3:

b3=0

if self.get('subject_nr')%4 ==4:

b4=0

Or am I completely off track here? My logic is that I only want to present 1 block hence the 0 (this is the only block to run) but it will be a different block (b1,2,3,4) depending on the participant number.

I would really appreciate you guidance on this.

Many thanks,

Kim

lvanderlinden

Hi @KimS

Thanks for your clear example of a simplified experiment!

6268.osexp

You were quite close using the modulo (%) method. In the attached file you will find an example of a script that shows a dolphin, a cat, a horse, or a dog trial, depending on the variable "subject_number". Is this what you were looking for?

Best wishes,

Lotje

KimS

Sorry for my delayed response, yes this is exactly what I needed. Thank you so much!

Kim