What is Levels of Measurement of Data?

 Sr  Measurement Definition Example
1 Nominal Classifies data into names, labels or categories in which no order or ranking can be imposed. The blood group of patients i.e A, B, AB & 0
 2 Ordinal Classifies data into categories that can be ordered or ranked. Students grade in examination Distinction, First Class, Second Class, Pass and Fail.
 3 Interval Ranks data, precise differences between units of measure exist, but there is no meaningful zero. IQ scores, it makes sense to talk about someone having an IQ 20 points higher than another person, but an IQ of zero has no meaning.
 4 Ratio It has all the characteristics of the interval level, but a true zero exists. Also, true ratios exist when the same variable is measured on two different members of the population. It makes sense to say that a 70 kg adult weights twice as much as a 35 kg child.