'randomising' trial order
in OpenSesame
Is it possible to pseudorandomise the order of the trials (which are currently picked at random) so that certain images don't appear one after the other?
For example, I'm building an experiment where different facial expressions are shown on different body postures and I don't want the same facial expression to appear twice in a row, even if it is on different body postures in each picture.
If anyone has an idea of how to do that, I'd really appreciate your help!
Comments
Hi Bal,
Have you looked at the documentation for the newly implemented pseudorandomization options?
You could add some constrains to the loop in the general script, for example avoid having the same stimulus appear twice in a row.
Best,
Laurent
I hadn't found this documentation, that solves my problem. Thanks!
Actually, when I tried this out it didn't work... when I added the "constrain variable mindist = 4" command in the general script (after all the setcycle commands), it disappears. Even if I choose the option to apply changes to the general script. I'm using an old version of open sesame (version 2.9.6) is there a way of doing it with this version?
Hi again,
The pseudorandomization options are specifically added in version 3.1, so my suggestion would be to upgrade. However, if you insist on using version 2.9 (e.g. because you are in the middle of testing) there are some older threads where you might find your solution:
Good luck!
Laurent
Ok, I'll have a look at those threads. Thanks for your help!