Which measurement type has an absolute zero point?

The measurement type that has an absolute zero point is ratio measurement. Ratio scales are characterized not only by the characteristics of other measurement types, such as having equal intervals and a meaningful order but also by the presence of an absolute zero. This means that zero on a ratio scale indicates the complete absence of the quantity being measured.

For instance, in measurements like weight and height, having a measurement of zero signifies that there is no weight or height present. This property allows for the calculation of ratios; for example, one can meaningfully say that an object weighing 10 kilograms is twice as heavy as an object weighing 5 kilograms.

In contrast, interval measurements do not possess an absolute zero point, meaning that even though they have equal distances between points (like temperature in Celsius), a zero point in this context does not reflect a total absence of the quantity. Nominal measurements categorize data without a numeric value (like gender or nationality), and ordinal measurements indicate order but do not quantify the differences between categories (like a satisfaction rating from 1 to 5), which also means they lack a true zero point.

Thus, ratio measurement stands out for its absolute zero, providing a foundation for meaningful comparison and calculation in quantitative research.