Creating Indicator Variables

Command:

Tools -> Create Indicator Variables...

In some situations, e.g. when classfying objects, it is helpful and meaningful to describe various states of a system not by a single (multi-level) variable, but by several binary indicator variables, which are 1 when a particular level occurs and 0 otherwise.

The command Tools/Create Indicator Variables... allows to split one or several categorical variables into a set of binary indicator variables. The resulting indicator variables are appended to the data matrix.

The variables which can be split into indicator variables show a tick box left to the variable name; all other variables cannot be converted to indicator variables. In order to create the indicator variables you have to click the button "Create Variables".

In the case you make a mistake the dataset can be reverted to its original state by clicking the "oops" button.

Hint:

Indicator variables can be generated from categorical variables (ordinal or nominal) only. If a non-categorical variable is to be used as the source for indicator variables, the variable has to be properly scaled to get the required number of levels and then be converted into an ordinal variable.