groupAssignment attribute

The groupassignment attribute determines how participants are assigned to between-subject conditions.

Member of

Syntax

/ groupAssignment = assignment

Parameters

Name

Type

Description

assignment

groupassignmentenum

Value	Description
groupNumber	Assignment based on group number.
random	Random assignment.
sessionNumber	Assignment based on session number.
subjectNumber	Assignment based on subject number.

Remarks

Between-subject groups can be defined using the expt or batch elements. Participants can be assigned to between-subjects groups based on the numeric subject id entered when launching the script, or by random assignment. This attribute specifies which method to use. By default, the subject id is used.

Examples

The following randomly assigns participants into one of 2 treatment conditions:

<expt conditionA>
/ subjects = (1 of 2)
/ groupassignment = random
/ blocks = [1=practice; 2=treatmentA; 3=test]
</expt>

<expt conditionB>
/ subjects = (2 of 2)
/ groupassignment = random
/ blocks = [1=practice; 2=treatmentB; 3=test]
</expt>