There are four main measurement scales in biostatistics:

Nominal scale: Categorizes data without a specific order (e.g., blood type).

Ordinal scale: Categorizes data with a specific order but unequal intervals (e.g., stages of cancer).

Interval scale: Has ordered data with equal intervals, but no true zero point (e.g., temperature in Celsius).

Ratio scale: Has ordered data with equal intervals and a true zero point (e.g., height, weight).