
43Introduction to Nonparametric Statistics
Like nominal scales, ordinal scales have the property of equivalence—
there is no relationship between numbers and choices on the scale. The
numbers are used only for classication purposes. In addition, ordinal scales
have a relational property that can show that an object (attribute, preference,
score) is greater than or less than any other object.
Statistical analyses that require addition and subtraction cannot be
performed on ordinal data; therefore, the mean and standard deviation are
inappropriate calculations for ordinal scales. The frequency and percent of
objects at each rank and the media