Interaction terms reflect the combination of two or more category values. For example, if a record’s age column is "50" and its sex column is "male", the value of the interaction term will be "(50, male)". Interaction terms are useful in creating complex tabulations and controlling for interaction effects in complex models.
To create a new interaction term:
By default, the name of the resulting column reflects the components of the interaction, but you can give the column a new name of your choosing. (Note that changing the name will not affect how the column is computed.)
See also: