No Repeats on Consecutive Trials (Condition) [30025]

This article applies to:
E-Prime 3.0
E-Prime 2.0
E-Prime 1.x

 
Detail
This sample illustrates a method to be used to permit randomization with the constraint that no two consecutive trials present the same condition.

Abstract
In this example, the conditions are entered as separate Nested List objects. Script is used to randomize the conditions in an array, and check for the criterion of consecutive trials presenting different conditions. When the random order is acceptable, the 'TrialList' object is then populated to set the 'Nested' column, and to run in 'Fixed' order. No two consecutive trials select from the same Nested List object, so the result is that no two consecutive trials are from the same condition.

This sample lists the Nested Lists in the 'TrialList' object to (1) include them in the tree structure where they will be used at runtime, and (2) allow them to be added to the Context object. If this is not done, the user must manually add them to the Context object via the 'Add' method.