Millisecond Forums

Between subject design

https://forums.millisecond.com/Topic22433.aspx

By amselie - 9/6/2017

Hi everyone.
Apologies in advance if this is a duplicate. I am using Inquisit 5 for running an experiment for my bachelor thesis and I so far I don't have any experience with programming. 

My issue is that I would like to have a between subject design with two conditions and randomized group assignment for my study, but I am not completely sure how to implement this. I tried creating two experiments with different blocks and it is running without any errors, but with this solution I guess that I won't obtain balanced groups. 

Is my solution correct or is there another way to create two different conditions? And is there a way to see in the data which condition a participant was assigned to?

Below I have an extract of the script that I'm using and any help would be appreciated. Thanks in advance! :)


<expt>
/ groupassignment = random
/ subjects = (1 of 2)
/ blocks = [1 = Consent; 2 = BodyMassIndex; 3 = Instructions; 4 = stroopThreat; 5 = Nachbefragung; 6 = DemographischeDaten]
/onexptend = [
values.completed = 1;
]
</expt>


<expt>
/ groupassignment = random
/ subjects = (2 of 2)
/ blocks = [1 = Consent; 2 = Instructions; 3 = stroopKontrolle; 4 = Nachbefragung; 5 = postBodyMassIndex; 6 = DemographischeDaten]
/onexptend = [
values.completed = 1;
]
By Dave - 9/7/2017

amselie - Thursday, September 7, 2017
Hi everyone.
Apologies in advance if this is a duplicate. I am using Inquisit 5 for running an experiment for my bachelor thesis and I so far I don't have any experience with programming. 

My issue is that I would like to have a between subject design with two conditions and randomized group assignment for my study, but I am not completely sure how to implement this. I tried creating two experiments with different blocks and it is running without any errors, but with this solution I guess that I won't obtain balanced groups. 

Is my solution correct or is there another way to create two different conditions? And is there a way to see in the data which condition a participant was assigned to?

Below I have an extract of the script that I'm using and any help would be appreciated. Thanks in advance! :)


<expt>
/ groupassignment = random
/ subjects = (1 of 2)
/ blocks = [1 = Consent; 2 = BodyMassIndex; 3 = Instructions; 4 = stroopThreat; 5 = Nachbefragung; 6 = DemographischeDaten]
/onexptend = [
values.completed = 1;
]
</expt>


<expt>
/ groupassignment = random
/ subjects = (2 of 2)
/ blocks = [1 = Consent; 2 = Instructions; 3 = stroopKontrolle; 4 = Nachbefragung; 5 = postBodyMassIndex; 6 = DemographischeDaten]
/onexptend = [
values.completed = 1;
]



If you want to exert control over which condition a given participant is assigned to, you should use /groupassignment = groupnumber. You then simply enter the respective group number (here 1 or 2) if you administer the script using Inquisit Lab. If using Inquisit Web you can supply the group number via a URL query parameter included in the link you give out to your participants, i.e. you'd give half of them a link that runs condition #1, and the other half a link that runs condition #2.

Also see https://www.millisecond.com/forums/Topic13856.aspx regarding how condition assignment works mathematically and how to determine which condition was administered.