Domain 1: Data Types & Measurement Nominal Data:  Categorical data with no inherent order or numerical value (e.g., gender, ethnicity, or "Yes/No"). Ordinal Data:  Data that can be ranked or ordered, but the mathematical distance between points is unequal (e.g., 1–10 pain scales or race finishing positions). Interval/Ratio Data:  Continuous numerical data with equal distances between points. Ratio data has a "true zero" indicating the total absence of the trait (e.g., height,