By tela - 9/8/2016
Is there any other way to assign participants to two conditions based on the subject id other than parity? Our experimenter needs to be blind to the conditions, and obviously she is not if parity rule is used. Can I manipulate subject ids, that are entered upon script launch, within Inquisit?
--tei
|
By Dave - 9/8/2016
See this recent thread (also works in Inquisit 4): https://www.millisecond.com/forums/FindPost19667.aspx
In case you don't care about exact pre-assignment, you can also simply set /groupassignment to random:
<expt>
/ subjects = (1 of 2)
/ groupassignment = random
...
</expt>
<expt>
/ subjects = (2 of 2)
/ groupassignment = random
...
</expt>
There will be no relationship between the entered subject id and the administered condition then -- assignment will be strictly random.
|
By tela - 9/14/2016
(for some reason my first post does not show up)
Thanks for the suggestions.
I am somewhat concerned about equal assignment of conditions, so I am a bit apprehensive to use random assignment.
The other solution you suggested (precondition) would work if I could do something like:
<include>
/ precondition = [script.subjectid < "5000" ]
/ file = "condition_1.iqx"
</include>
We have generated random IDs for participants, but they can be sorted. One more question, can precondition be included in the block element so that I don't have to separate the two conditions into separate files? Or perhaps I could use branch for that? Currently I have for condition 1:
<expt>
/ subjects = (1 of 2)
/ groupassignment = subjectnumber
/ preinstructions = (welcome_p)
/ blocks = [1 = consent_b; 2 = practice_b; 3 = subprime_trust_b; 4 = playerA_b; 5 = donation_b]
</expt>
|
By Dave - 9/15/2016
See https://www.millisecond.com/forums/FindPost19691.aspx
|