What distinguishes ratio data from other types of data?

Ratio data is characterized by having a natural zero point, which distinguishes it from other types of data. This natural zero point allows for the meaningful interpretation of ratios between values. For example, in a ratio scale, a value of zero signifies the absence of the quantity being measured, such as height, weight, or temperature in Kelvin. This means that not only can you compare two values to see how much one is greater than the other, but you can also say that one value is twice or three times another value in a way that makes sense because of the absolute nature of the zero point.

In contrast, other types of data, like categorical data, do not have this feature and are simply classified into categories without any inherent order. Ordinal data can be ranked in order, but it does not allow for the measurement of the exact differences between values, while interval data lacks a true zero but allows for meaningful differences. Therefore, the defining quality of ratio data is its absolute zero point, which enables a full range of mathematical operations and meaningful comparisons.