groups attribute

Member of

<batch> <expt>

Syntax

/ groups = (integer, integer, integer, ... of modulus)

Parameters

Name	Type	Description
integer	integer	A positive integer indicating which group ids should run the experiment.
modulus	integer	A positive integer indicating the modulus.

Remarks

The groups attribute allows you to run different batch or expt depending on the group id provided when the script is run. A given expt or batch will be run if the the following is true:

integer = remainder( group id / modulus )

Multiple expts and batches can be defined in the script, allowing different group ids to be assigned to different experimental conditions. A single group id can be assigned to multiple expts, in which case all of the assigned expts will be run for that group id in the order they appear in the script.

Examples

The following expt is run for odd numbered groups:

<expt>
/ blocks=[1-20=noreplace(testtrials, distractortrials)]
/ groups = (1 of 2)
</expt>

The following expt is run for even numbered groups:

<expt>
/ blocks=[1-20=noreplace(testtrials, distractortrials)]
/ groups = (2 of 2)
</expt>

The following batch is run for group id 3 and every subsequent 3rd group id (e.g., 3, 6, 9, 12, ...):

<batch>
/ file="experiment3.iqx"
/ groups = (1 of 4)
</batch>

The following expt is run for second of every four groups (e.g., 2, 6, 10, 14, ...):

<expt>
/ blocks=[1-20=noreplace(testtrials, distractortrials)]
/ groups = (1 of 4)
</expt>