Peoples' opinions aren't always cut and dry or black and white. Sometimes researchers ask the same question in a variety of ways to find out how firmly someone thinks or believes something. At other times an issue has several ways to look at it. Different questions about the same thing may help get at true opinions about each one.

And surprisingly, sometimes a question asked two different ways is really getting information about two different things. This is called nonredundant information. There can be more than one way to look at a subject. Questions that seem repetitive may be good at collecting nonredundant information.