Question

What is the difference between the scales of measurement? Specifically Ordinal, Interval and Ratio scales of measurement because they are all very similar. Please provide good examples and explanation so I can understand the difference and not be confused when trying to determine/ solve for a variable.

Example:

Each voter was asked to rate their support for the current government on a scale from 0-100 (zero indicates no support whatsoever, while 100 indicates fully supporting the current government).

Voter support is the dependent variable but is it ordinal or interval scale of measurement?

Answer 1

There are four scale of measurement -

1.Nominal

2.Ordinal

3.Interval

4.Ratio

Nominal scale-

It deals with non-numeric variables or where observation have no value. This scale has no order. They are basically 'labels' or 'tags'. By their nature they are discrete. One example of nominal scale can be taken as 'sex' . Students of a class can fall in either of two classes - 'male' or 'female' .

Ordinal scale -

This scale is used where order matters but not the difference between values.It can measures non-numeric concepts. Example of ordinal scale can be taken 'Grade' in test. In a class, test Grade A,B,C is given to the students. These grades are in ordinal scale.

Interval scale -

This scale is a quantitative measurement scale. In this scale, the difference between two variables is meaningful. This scale doesn't have ''true zero''.This scale can be discrete or continuous.This scale is preferred over nominal and ordinal scale because both the scale are qualitative in nature while interval scale is quantitative in nature and we can find the difference between values. Example can be taken as temperature of city. The difference between 90⁰ C and 100⁰ C is same as 60⁰ C and 70⁰ C which is 10⁰ C..

Ratio scale -

This scale tell exact value between units. This scale is same as interval scale with major difference that here zero is meaningful. Ratio scale is the most informative scale. Also doesn't have a negative number.This scale is quantitative in nature. Example height ,height ,age of students of a class is taken in ratio scale.

In the given example -Each voter was asked to rate their support for the current government on a scale from 0-100 (zero indicates no support whatsoever, while 100 indicates fully supporting the current government).

Voter support is the dependent variable but is it ordinal or interval scale of measurement?

Answer- In the example given ,voter rating is in ordinal scale. Since there is a scale from 0-100. They are in order but the difference between the order is of not much important. What matters here is order.