They are a pair of variables in which we classify qualities (attributes) of the research elements into categories that can be ordered. They are known as Ordinal Qualitative Variables (they can be ordered in ascending or descending order, eg level of education – illiterate, 1st grade, 2nd grade, 3rd grade and Postgraduate). In this case, there are categories that are greater than others or there is a category that is better than another, that is, there is order between these qualities.