Nominal data are best described as:

• A. Categories where order matters
• B. Categories where order does not matter
• C. Numbers with equal intervals
• D. Values with a true zero

Answer: (B)

Nominal data are categories that have no natural order or ranking. They are labels used to name groups, and you can count how many fall into each category or compute proportions, but you cannot say that one category is higher or lower than another. Examples include blood type, eye color, or country of residence. Even if you assign numbers to these categories, the numbers are just labels and do not indicate quantity or magnitude.

Because there’s no inherent order, you don’t use means or medians to describe nominal data; you summarize with frequencies and proportions, and you compare groups with nonparametric methods like the chi-square test. This contrasts with data described as ordinal (where categories do have an order), interval (numbers with equal intervals between values), or ratio (numbers with a true zero).