An IP designs a survey to assess the effectiveness of an infection prevention and control in-service course. The choices after each question are: Unsatisfied, Satisfied or Very Satisfied. These are examples of which kind of scale?

• A. Ordinal
• B. Nominal
• C. Interval
• D. Ratio

Answer: (A)

The key idea is that the responses represent an ordered set of categories. Unsatisfied, Satisfied, and Very Satisfied show a clear rank: one category indicates more satisfaction than another, but we don’t assume the distance between categories is the same. That makes this an ordinal scale.

This isn’t nominal because there is a meaningful order among the categories. It isn’t interval because we can’t assume equal intervals between categories (the difference in satisfaction between “Unsatisfied” and “Satisfied” isn’t guaranteed to be the same as between “Satisfied” and “Very Satisfied”). It isn’t ratio because there isn’t a true zero point or proportional distances.

So, the best description is ordinal, which is typical for Likert-type satisfaction questions.