selectionrate attribute

The selectionrate attribute determines when a new item should be selected from the pool.

Applies to

Syntax

/ selectionrate = rate

Parameters

rate

One of the following values:

Value	Description
always	Select a new item everytime.
trial	Select a new item once per trial.
block	Select a new item once per block.
experiment	Select a new item once per experiment.

Remarks

By default, a counter will select one item each trial. As an example, imagine a trial that presents a given stimulus multiple times, and that stimulus uses a counter to select from the set of items. If the selectionrate is set to trial, an single item is selected at the beginning of the trial, and that same item is presented each time on that trial. When the next trial occurs, a new item is selected, and that item is presented multiple times. However, if the selectionrate is set to always, each time the stimulus is presented on that trial, a new item is selected.

Examples

The following causes all counters in the script to maintain their selection pools for a total 20 blocks:

<defaults>
/ selectionrate = 20
</defaults>