Counterbalancing blocks for participants

Pari

Hi,

I am planning to counterbalance block presentations in my experiment for participants. Specifically, I would like to ensure that when the var.subject-nr is odd, the first experimental loop (i.e., 'color-block') is presented before the second block ('shape-block'), and vice versa when the var.subject-nr is even.

I have attached a photo of my experiment structure for reference. Any guidance on how to implement this into my script would be greatly appreciated.

Thank you for your assistance.

Best regards,

PariShad

Fab

Hi @Pari,

One simple way of achieve that is to include both of your blocks (color_block and shape_block) into a higher-level loop with 2 rows, and to use some code to store identifiers for the two conditions in an order depending on the subject number's parity. Then you can set a variable taht will et incremented after each trial of the higher-level loop (that is, after the first condition (color or shape) has been run), and use that set the a condition variable to "shape" or "color" and use the "Run if" property to only ruin the apporpriate condition.

I attach an implementation to illustrate it. It's fairly simple, so I think you should be able to work out how it works and adapt your task accordingly:

Counterbalanceblockorder.osexp

Best,

Fabrice.

noob768

Hi @Fab

Thank you for the information. This looks easy to do. But, is there a way to add a higher loop that will include the easy and difficult loop?

Fab

Hi @noob768,

Not sure I understand your question. The example I provided above presented two blocks in counterbalanced order across participants. So, you can use it to present a difficult and an easy block to participants, with half the participants doing easy then difficult, and the others doing difficult and then easy.

If this is not what you need, please describe more clearly what you are trying to achieve and I'll get back to you.

Regards,

Fabrice.