Which of the following is an example of a nominal data scale?

• A. Weight
• B. Color categories
• C. Temperature in Celsius
• D. Customer satisfaction rating

Answer: (B)

Nominal data are categories used only for labeling or identification, with no natural order and no meaningful numeric differences between categories. Color categories are a classic example: you can group items by color and count how many fall into each group, and you can say which color is most common, but you cannot say one color is greater than another or compute a meaningful average across colors.

This differs from other scales. Weight is a ratio scale, which has a true zero and meaningful arithmetic—you can add, subtract, or compare ratios of weights. Temperature in Celsius is an interval scale: you know the differences between temperatures, but zero does not represent an absence of temperature, so you can’t form legitimate ratios. Customer satisfaction rating is usually ordinal: you can say one level is more satisfied than another, but the intervals between levels aren’t guaranteed to be equal, so arithmetic operations aren’t appropriate.