For example, the demographic data elements of race and religion are measured at the nominal level. This means that the values consist of categories such as white, African American, Native American, Asian, and other. With nominal level
data, no category is better than another, and the difference between categories cannot be determined. For example,
neither Catholic nor Protestant is better than the other, and whether Catholic is closer to Protestant or closer to Jewish
is not known. The only interpretation possible is that two subjects are or are not the same on this variable.