Randomly assign conditions?

[jarvis24]

[from support emails]

Is there a way to randomize the condition that subjects are placed into? Right now the experimenter has to select the condition manually (and enter the participant id#), but as far as I can tell there is no way to have this done automatically.

The only work around that I found was by creating a response.xls file with a skipto value that uses the rand() command in excel to randomly move Ss to a different position in a questionnaire. So that I can make my first condition questions 2-10, my second condition 11-20, etc… Then the first question simply randomly assigns Ss to either skip to question 2 or 11. I think that this should work, but would love to know if you have other solutions.

I would also really like to be able to have some sort of unique id created for each subject. I typically run on multiple computers simultaneously and it would be nice if MediaLab could create an unique id per subject per computer. I can again do something like create a new variable with the rand() function, but then I am not assured that all IDs will be unique (though I’m guessing it is highly unlikely that something like a 7 digit number will reappear).