The Role of an attribute reflects the part played by that attribute in an ExampleSet. Changing the role of an attribute may change the part played by that attribute in a process. One attribute can have exactly one role. This operator is used to change the role of one or more attributes of the input ExampleSet. This is a very simple operator, all you have to do is to select an attribute and select a new role for it. Different learning operators require attributes with different roles. This operator is frequently used to set the right roles for attributes before applying the desired operator. The change in role is only for the current process, i.e. the role of the attribute is not changed permanently in the ExampleSet. The Set Role operator should not be confused with the Rename operator or Type Conversion operators. The Rename operator is used to change the name of an attribute. Many Type Conversion operators are available (at Data Transformation/Type conversion/) to change the type of attributes e.g. the Nominal to Binominal operator, the Numerical to Polynomial operator and many more.
Broadly roles are classified into two types i.e. regular and special. Regular attributes simply describe the