Dear forum,
I’m a little trapped by a tricky design for a false memory experiment. The issue is that I have 60 sets of 5 associates (e.g., ADD: subtract, sum, plus, multiply, maths), half of which will be presented randomly (i.e., any associate from any list can be presented as part of a 5 stimuli sequence before a textbox appears for recall), and half of which need to be presented as complete sets (i.e., “lists”) in the sequence specified (e.g., 1 = subtract, 2 = sum, 3 = plus, 4 = multiply, 5 = maths). Unfortunately, the sets that become “random” and those that become “lists” are ideally random too, however, to satisfy the constraints (the researchers would REALLY like for all stimuli to be presented to each participant, and NEVER to appear more than once) this assignment seems to need to be done at the beginning of the experiment.
For completeness, there is also a picture element. Specifically, the design is 2 (random, list) by 3 (no picture, matched picture, unmatched picture). This works fine.
So, I hit problems if I have “random” sequences presented first –because single items are chosen from too many whole sets (e.g., 10 random sequences can draw from 50 “lists”, leaving only 10 unsampled lists rather than the 30 needed) . This will be true for 50% of participant. I figure that if I could randomly assign sets to be used for “random” versus “lists”, I could fix this, but I can’t seem to work out how to do this (probably at the experiment level).
The code is huge (and includes 300 images too) so I have left it out. Any suggestions on how this could be achieved would be GREATLY appreciated!
Thanks, Leah