Ordinal Scales of Measurement

In ordinal scales, values given to measurements can be ordered. One example is shoe size. Shoes are assigned a number to represent the size, larger numbers mean bigger shoes so unlike the nominal scale that just reflects a category or class, the numbers of an ordinal scale show an ordered relationship between numbered items - we know that a shoe size of 8 is bigger than a shoe size of 4. What you can't say though is that a shoe size of 8 is twice as big as the shoe size of 4.

So numbers on an ordinal scale represent a rough and ready ordering of measurements but the difference or ratios between any two measurements will not be the same. As for the nominal scale with ordinal scales you can use textual labels instead of numbers to represent the categories.

So for example a scale for the measurement of patient satisfaction with the care they received in hospital might look like this:

Not satisfied | Fairly satisfied | Satisfied | Very satisfied