Sequential stimuli thats randomised

[ftornay at ugr.es]

Mensaje citado por Khalilah Khan <K.Khan at warwick.ac.uk>:

> Hello e-prime users
>
> I have a list of 144 stimuli that I wish to present. There are 12 images each
> in the 12 groups. I wish to run 12 images in sequential order but then wish
> to randomise the groups. How can I do this?
> Thank you for your help.
>
> Khalilah Khan
>
> IACS, Psychology
> University of Warwick
> Coventry
>
>


This is similar to the way we randomize task sequences in our lab when using a
task-switching paradigm

One way of doing it is to set up 12 different procedures, each with a list that
includes the 12 stimuli in each particular group. In the procedure attribute
include your trial proc. Those lists should be ordered sequentially.
Then setup a list with 12 levels and write the suitable procedure for every
group. That list should be ordered at random.

You end up having a higher-order list (with the groups) which selects a
particular group-procedure at random. Then the program goes on to run the 12
trials in that group sequentially.

Hope this helps, feel free to ask if I have not made myself clear enough.

Francisco Tornay
University of Granada
Spain