The figure shows an example. There are three statements describing attitudes towards immigration. To scale these statements, we have to assign numbers to them. We'll present several different approaches below. But first, I have to clear up one of my pet peeves.
People often confuse the idea of a scale and a response scale.
A response scale is the way you collect responses from people on an instrument. But, if all you are doing is attaching a response scale to an object or statement, you can't call that scaling. As you will see, scaling involves procedures that you do independent of the respondent so that you can come up with a numerical value for the object. The differences are illustrated in the table below. First, sometimes we do scaling to test a hypothesis.