All content on this site is by and copyright ©1994-2017 Tonio Loewald, unless otherwise specified. Best viewed in Firefox, Safari, or IE8.

Random Variables

Watch Video Tutorial

To set up random variables in a questionnaire, select Questionnaire | Preferences and then click the Randomization tab.

Setting up a random variable requires the following steps:

  1. Click the Add button under Random Variables.
  2. Click on the new variable to edit its name. A random variable's name is exactly the same as the column name of a question.
  3. Click Add under Possible Values for [Your Variable] as many times as you like to create as many possible values for the variable as you like.
  4. Click on the values to edit them to suit your purposes (in the example we've made one value "True" and the other "False").

You can modify the Weight of values to make them more or less likely (e.g. if you want the variable to be True twice as often as False, give True a weight of 2 and False a weight of 1). Fractional weights are supported, but we recommend using integer values for weight.

Related Topics

Conditional Sections, Conditional Sections (Example)

Notes

Random variables are assigned values when the user starts filling it in. Once the user starts, the variables remain constant unless they variable's name matches the column name of a question.

If you want to see the value assigned to a random variable inside a form you can create a Text Response question with the same column name as the variable's name. The text response will display the variable and let you change it (e.g. for testing purposes).