RBG - Randomization Between Groups

QuickInfo

All trials sharing the same RBG value define a group to be kept together. If multiple groups are defined, then DirectRT will present the groups in a random order. Identical to the MediaLab function of the same name.

Value

Any positive integer value

Details

You may wish to randomly order and present entire groups of trials in your questionnaire (e.g., randomizing which of four sets of 20 trials is presented 1st, 2nd, 3rd and 4th). To do this, assign the same RBG value in the bgr column to all of the items you want to keep together. For example, if you have five sets of ten trials and you want to randomize the order in which these 5 groups of trials are presented, then assign each group a different number and make sure all the items within each group share the same number for that group. The items within each group will all stay together, but the groups themselves will be randomly ordered. Items assigned a value of "0" or "none" in the rbg column will not move.

**Note that all items within a group must be sequential in the questionnaire.

Note for ease of analysis, trials are written to the data file in the order they occur in the input file, not in the randomized order in which they are presented. However an "Order" variable is also written to indicate the sequential order in which the trials actually occurred.

Example

See Samples, RBG

See Also

RWG - Randomizing Within Groups

Using Random Values