Tutorial: RWG (13/21)

Location

…\DirectRT\samples\3 ordering trials\rwg.csv

Description

The following text is taken from the interactive tutorial located in the help folder after installation.  You may prefer to print these pages rather than having them on-screen during the tutorial.

The next three samples show some of the basic methods for the quick and easy randomization of trials.

The first method, RWG stands for Randomization Within Groups. Open the input file and look at the RWG column. Every item that shares the same RWG value with another belongs to the same RWG group. Items sharing the same RWG value will be randomized with each other no matter where they are in the list of trials. The only exception is if an item is assigned an RWG value of 0, then it will stay exactly where it is. Often, instruction trials will be given an RWG value of 0.

Try running the session and see what happens. Notice that the stimulus for each trial is the trial number itself so that you can observe the effects of the randomization.

As an exercise, try randomizing all the trials by assigning them each an RWG value of 1.