Introduction
There are many cases where you need to transform the values of variables you have collected. Sometimes you want to change the value of the original variable. This overwrites the original value and is usually not recommended. Usually you want to create a new variable containing the transformed values.
One class of transformations is called recoding. Recoding is a many-to-few transformation. Examples include transforming a continuous variable into a few categories and transforming a variable with many categories into one with just a few.