Random location without replacement?
Random location without replacement?
[edited from support email]
I'm working with directRT amd I'm trying to set up two paired images in the same screen but I want their location to be selected at random from two possible places. My question is how can I make DirectRT to select for the second paired stimulus, the location that was not assigned at random for the first image.
Right. It's the "without replacement" randomization part of this that is tricky because that eliminates the random value function and you can't use stim lists for locations.
I think you can still do this easily though because you only have two locations. Try creating a stim list for each trial. In the stim list place the two images you want presented. Then, in your input file, list two sequential stimuli, one in position #1 and the other in position #2. Use the $ function to draw the stimuli randomly without replacement from your stim list. Voilà.
Does that make sense?
-Blair
