By GeeP - 9/10/2014
Hi All,
In the current study that I am designing, subjects will be doing 3 categorization tasks in a fixed manner. For example, In task 1, subjects are asked to categorize 'stars' and 'triangles' that immediately follow faces. In task 2, they will do an LDT with the faces from the previous task as primes. There are 4 categories of target words and with the counterbalancing, matching, and response key assignment etc., there will be at least 4 conditions to which Ps have to be randomly assigned. In task 3, they will do an AMP with randomization applied to response keys. I am confused as to how to set up the randomization for response keys, such that subjects will be automatically assigned to one of two response key set-ups. The response keys are as follows:
Task 1: E = Star; I = Triangle
: E = Triangle; I = Star
Task 2: E = Word; I=Nonword
: E = Nonword; I = Word
Task 3: E= Pleasant; I = Unpleasant
: E = Unpleasant; I = Pleasant
There will be basically two groups of subjects and each group will complete a slightly modified task 1. For task 2, subjects from the any of the two groups from task 1, will have 4 conditions to be assigned to and all subjects irrespective of the groups will complete the same AMP. Although this is the basic set up, the key assignment has to be incorporated such that equal number of subjects get assigned to both response key assignment. I know that I can create different blocks with different combinations of response key assignments and set up several experiments, but is there a more efficient way to accomplish this. Any help would be greatly appreciated!
Thanks in advance!
-G
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By Dave - 9/10/2014
It works the same as any other between-subjects condition. For the sake of simplicity, suppose you have two groups. Group 1 ought to press the spacebar, group 2 ought to press the ENTER key instead.
<values>
/ myresponsekey = 1
</values>
<expt>
/ onexptbegin = [values.myresponsekey=57]
/ blocks = [1=myblock]
/ subjects = (1 of 2)
/ groupassignment = groupnumber
</expt>
<expt>
/ onexptbegin = [values.myresponsekey=28]
/ blocks = [1=myblock]
/ subjects = (2 of 2)
/ groupassignment = groupnumber
</expt>
<block myblock>
/ trials = [1=mytrial]
</block>
<trial mytrial>
/ isvalidresponse = [trial.mytrial.response==values.myresponsekey]
</trial>
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By GeeP - 9/11/2014
Thanks Dave!!! This was helpful!
-G
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