counterbalancing with web delivery


counterbalancing with web delivery

Author
Message
Paul Lattimore
Paul Lattimore
New Member
New Member (18 reputation)New Member (18 reputation)New Member (18 reputation)New Member (18 reputation)New Member (18 reputation)New Member (18 reputation)New Member (18 reputation)New Member (18 reputation)New Member (18 reputation)

Group: Forum Members
Posts: 1, Visits: 1
Hi,
I'm using Single target IAT based on script available in millisecondlibrary. I will run it on web so I need to figure out how to counterbalance allocation to compatible and incompatible categories. The current PC based script does this by assigning group number (1,2) on start-up. That's fine if you are sitting beside the participant. Participants will be promted via wb delivery to enter 8-digit alphanumeric ID.
 Can anyone tell me how I would write the counterbalancing into the script or use some other means to ensure even allocation.
Thanks,
Paul
The script is currently set for PC platform as follows:

Groupassignment is done by groupnumber

<expt>
/subjects = (1 of 2)
/groupassignment = random
/ blocks = [1=practice_compatibletest; 2=compatibletestinstructions; 3=compatibletest;
 4=practice_incompatibletest; 5=incompatibletestinstructions; 6=incompatibletest; 7=summary]
/onexptend = [values.completed = 1]
</expt>

<expt>
/subjects = (2 of 2)
/groupassignment = random
/ blocks = [1=practice_incompatibletest; 2=incompatibletestinstructions; 3=incompatibletest;
4=practice_compatibletest; 5=compatibletestinstructions; 6=compatibletest; 7=summary]
/onexptend = [values.completed = 1]
</expt>



Dave
Dave
Supreme Being
Supreme Being (428K reputation)Supreme Being (428K reputation)Supreme Being (428K reputation)Supreme Being (428K reputation)Supreme Being (428K reputation)Supreme Being (428K reputation)Supreme Being (428K reputation)Supreme Being (428K reputation)Supreme Being (428K reputation)

Group: Administrators
Posts: 8.9K, Visits: 38K
Paul Lattimore - Tuesday, March 6, 2018
Hi,
I'm using Single target IAT based on script available in millisecondlibrary. I will run it on web so I need to figure out how to counterbalance allocation to compatible and incompatible categories. The current PC based script does this by assigning group number (1,2) on start-up. That's fine if you are sitting beside the participant. Participants will be promted via wb delivery to enter 8-digit alphanumeric ID.
 Can anyone tell me how I would write the counterbalancing into the script or use some other means to ensure even allocation.
Thanks,
Paul
The script is currently set for PC platform as follows:

Groupassignment is done by groupnumber

<expt>
/subjects = (1 of 2)
/groupassignment = random
/ blocks = [1=practice_compatibletest; 2=compatibletestinstructions; 3=compatibletest;
 4=practice_incompatibletest; 5=incompatibletestinstructions; 6=incompatibletest; 7=summary]
/onexptend = [values.completed = 1]
</expt>

<expt>
/subjects = (2 of 2)
/groupassignment = random
/ blocks = [1=practice_incompatibletest; 2=incompatibletestinstructions; 3=incompatibletest;
4=practice_compatibletest; 5=compatibletestinstructions; 6=compatibletest; 7=summary]
/onexptend = [values.completed = 1]
</expt>



<expt>
/subjects = (1 of 2)
/groupassignment = random
/ blocks = [1=practice_compatibletest; 2=compatibletestinstructions; 3=compatibletest;
 4=practice_incompatibletest; 5=incompatibletestinstructions; 6=incompatibletest; 7=summary]
/onexptend = [values.completed = 1]
</expt>

<expt>
/subjects = (2 of 2)
/groupassignment = random
/ blocks = [1=practice_incompatibletest; 2=incompatibletestinstructions; 3=incompatibletest;
4=practice_compatibletest; 5=compatibletestinstructions; 6=compatibletest; 7=summary]
/onexptend = [values.completed = 1]
</expt>

The condition assignment in the code you posted is _not_ done by group number. It is set to random, i.e. the condition assignment is basically like a coin toss, and the condition administered is unrelated to either the participant's subject id or her/his group number. If you want condition assignment based on group number, you should do

<expt>
/subjects = (1 of 2)
/groupassignment = groupnumber
/ blocks = [1=practice_compatibletest; 2=compatibletestinstructions; 3=compatibletest;
 4=practice_incompatibletest; 5=incompatibletestinstructions; 6=incompatibletest; 7=summary]
/onexptend = [values.completed = 1]
</expt>

<expt>
/subjects = (2 of 2)
/groupassignment = groupnumber
/ blocks = [1=practice_incompatibletest; 2=incompatibletestinstructions; 3=incompatibletest;
4=practice_compatibletest; 5=compatibletestinstructions; 6=compatibletest; 7=summary]
/onexptend = [values.completed = 1]
</expt>

To ensure approximately even assignment to conditions on the web, then, select e.g. sequentially generated group numbers in the web experiment's settings when you upload and configure the script.

GO


Reading This Topic


Login
Existing Account
Email Address:


Password:


Social Logins

Select a Forum....






Millisecond Forums


Search