Contents of Measurement Scales and Computation

<br />Measurement Scales and Computation<br />

Nominal: Only one is to count
Ordinal: No for addition, subtraction, multiplication, and division; but OK for statistical procedure based on rank;
Interval: OK for addition and subtraction, but not multiplication and division since no absolute zero (e.g., 50 degrees is not two times 25 degrees); most of stat procedures can be used;
Ratio: All math operations (+, -, x, /) and stat procedures (but not necessary in the meaning of a number)