What is the difference between nominal and ordinal data?

Nominal and ordinal data are both types of categorical data. The key difference between the two is that while nominal data cannot be ordered or ranked, ordinal data can. Nominal data represents simple categories or groups with no order or priority. Examples include colors or city names. Ordinal data, on the other hand, represents categories that can be ranked or ordered. Examples include Likert scale data (e.g., a five-point scale from "strongly disagree" through "strongly agree"), educational level (high school, BA, MA, PhD), etc.