psychopy.org | Reference | Downloads | Github

Interleave two different (though related) staircases?

If this template helps then use it. If not then just delete and start from scratch.

Win10
1.84.3
Standard Standalone

Hi all,
I’m trying to do something a bit unusual (I think) and I wanted to see if anyone knew if it was even possible.
I want to create a staircase task in which people categorize sounds from a /ba/ to /da/ continuum, so that I can find their perceptual boundary and psychometric slope. However, I want to present them with two different /ba/ to /da/ continua. So this would be two different staircase runs (not just multiple interleaved staircases examining the same continuum, which is already possible).
I could easily do the two staircases sequentially, but in order to help avoid order effects or learning effects, I’d like to run these two staircases at the same time (interleaved). Is this possible?
Thanks,
Mark

The current system for interleaved staircases is designed for exactly this (although it can also run multiple identical staircases)!

You can have a column in your conditions file for the interleaved stairs that acts just like a variable in standard conditions files, except that it now specifies the variable for all trials on that staircase. In your case you might have a variable audioFile that you then used to load your sound in the routine as usual

Hi,
Thanks Jon, that’s great to hear! I had already implemented that, and it seemed to be working fine (each staircase was converging on a plausible boundary estimate) but I thought that maybe I was abusing the proper design of the staircase and so the values of “level” that were being generated may not be a valid measurement since the staircases would not converge to a common estimate (as they are measuring boundaries on different continua). So far when I have used interleaved staircases they have been on the same continuum, so I was worried that there being two different psychometric slopes involved here would invalidate my procedure.
Thanks a million!
Mark

Yes, the staircases won’t converge on the same thing, but that really is what you want. They will store their own independent histories and responses.