Survey Tabulation > Understanding variables > Derived variables
 
Derived variables
Derived variables are variables that have been created from other variables. For example, you might create a derived variable to show the sum of the values stored in two or more other numeric variables. Another common example is creating a total awareness variable which combines the responses to questions about brands that are known. For example, market research surveys frequently ask respondents to:
Name their favorite brand of a product (such as washing powder).
Name any other brands of the product they can remember.
Look at a list of brands of the product and say which ones they have heard of or used before.
Typically, the category lists for each of these questions are identical. The first of these questions is usually a single response question, the second question (known as a spontaneous awareness question) and the third question (known as a prompted awareness question) are usually multiple response questions. Creating a "total awareness" derived variable makes it easy to analyze the combined responses to the three questions.
Derived variables can be numeric, categorical, text, date, or Boolean variables and in practice they work just like any other variable of the same type (except that you cannot base a new variable on a derived variable). For example, you can add a derived categorical variable to the side or top of your table and it will work just like an ordinary categorical variable.
You can create derived variables in UNICOM Intelligence Reporter - Survey Tabulation using the Copy, Merge, and New Advanced commands on the Variables menu. See Creating variables for more information.
See also
Understanding variables