Hi. I am creating an IAT and have gotten a bit stumped on randomization.

For example, on a block with flower and good on the right and insect and bad on the left, I have 5 words per stimulus category in my text files. I would like to run 30 trials in the block in random order except that I would like the trials to alternate between either flower/insect and good/bad. So the trials would be random, but alternate between presenting a target and then adjective stimulus.

However, I haven't been able to figure out how to randomize this way. In looking at the sample IAT input file, I see that they are randomized in this way, except that they are running 8 trials with an equal number of trials per category. With my setup of 30 trials, this doesn't work because some of the target and adjective stim lists automatically get more trials because of the way they must be listed. Is there a way to do what I'm trying to do?