Hi,

I want to randomize the order of two experimental features of an experiment. On the forum I found a script similar to what I wrote below, with the exception that in the posted script there is an assignment /subjects = 1 of 2 and subjects = 2 of 2. I am not sure I understand exactly the purpose of this assignment. Without it, as the script below is written, I am not getting the randomization I want. I have read the help files on subject, but it is still not clear to me exactly what subject is referring to (i.e., participant #, or is subject jargon for something else?). Please advise.

<batch>

/ file="Welcome.iqx"

/ file="evaluativeIAT.iqx"

/ file="stereotypeIAT.iqx"

/ file="emotion recognition task.iqx"

/ file="baer mindfulness.iqx"

/ file="PhilMindfulness.iqx"

/ file="IQHatfordShipley.iqx"

/ file="AAQ.iqx"

/ file="interpersonal reactivity index.iqx"

/ file="nonattachment.iqx"

/ file="needforcognition.iqx"

/ file="BFI44.iqx"

/ file="selfcare.iqx"

/ file="end.iqx"

/groupassignment = random

</batch>

<batch>

/ file="Welcome.iqx"

/ file="stereotypeIAT.iqx"

/ file="evaluativeIAT.iqx"

/ file="emotion recognition task.iqx"

/ file="baer mindfulness.iqx"

/ file="PhilMindfulness.iqx"

/ file="IQHatfordShipley.iqx"

/ file="AAQ.iqx"

/ file="interpersonal reactivity index.iqx"

/ file="nonattachment.iqx"

/ file="needforcognition.iqx"

/ file="BFI44.iqx"

/ file="selfcare.iqx"

/ file="end.iqx"

/ groupassignment = random

</batch>

You need the /subjects attribute to define between-subjects groups (here: two groups of different file orders). /groupassignment determines how participants will be assigned to one of the available groups. You'll find this covered in the documentation and in the forum thread you mentioned.