
<p>There are four different scales of measurement that go along with these different ways that values of a variable can differ.</p>
<p><em>Nominal scale</em>. A nominal variable satisfies the criterion of identity, such that each value of the variable represents something different, but the numbers simply serve as qualitative labels as discussed above. For example, we might ask people for their political party affiliation, and then code those as numbers: 1 = “Republican”, 2 = “Democrat”, 3 = “Lib