Randomising images

MaximeL

Hello,

I am trying to create an experiment where images are shown from a potential bank.

There are 8 images (4 pairs of images, but they come in 2 different conditions). In each block, the participant needs to see one condition/form of the image pairs. This happens for 4 blocks.

How would I go about randomising the order of the 4 pairs of images, and which condition the participant gets for each block?

Please could someone help with this?

Thank you,

Maxime

Fab

Hi @MaximeL,

I'm having some trouble understanding your design. Could you possibly clarify it? Then I'd hopefully be able to make some suggestion.

Best,

Fabrice.

MaximeL

Hi @Fab ,

Yes of course - to clarify:

There are 4 conditions. For each condition, the person has a choice of seeing one of 2 images. How do I randomise which image the participant sees? Should I use the shuffle button to equally distribute image 1 and 2 for each condition?

Hope this makes it clearer!

Thank you,

Maxime

Fab

Hi @MaximeL,

Ok, so you want to randomize the order of 4 blocks, and in each block the trials show two pictures of which you to randomize.

To randomize the order of your blocks, the best and simplest way is to nest loops. You start by creating a loop that will contain the list of blocks, then loops within it, one for each block. What you'd want to do is to use the "Run if" feature of the block's loop to determine which block should run when:

As for randomizing the two pictures in each trial, you can use the shuffe_horiz function. See https://forum.cogsci.nl/discussion/5892/show-multiple-images-at-the-same-time-at-random-positions for an example.

Good luck!

Fabrice.