Measurement Scales and it's Types

  Measurement scale is a classification that describes the nature of information within the values assigned to variables.

In statistics, there are four data measurement scales. These are simple ways to sub-categorize different types of data.

i.Nominal

It is used for labeling variables. It is simply called “labels”. It is the lowest measurement level. It is assigned to items that is divided into categories without having any order or structure. It used for the purpose of identification and ordering for ascending or descending. The only mathematical operation we can perform with nominal data is to count. For eg:

1.     What is your Gender?

a.      Male 

b.     Female

2.     Where do you live?

a.      Northern hemisphere

b.     Southern Hemisphere

        ii. Ordinal

The order of the value is important but the differences between each one is not really known. It measures non-numeric concept like satisfaction, happiness, discomfort, etc. It ranks responses. It has the property of identity and magnitude. The distance between scale point is not scale and not the relative positional distances.

Eg: How do you feel today?

a.      Very happy

b.     Unhappy

c.      Okay

d.     Happy

e.      Very happy

iii.Interval

The order and the exact differences between the values is known. It has an interval scale because it assumes to have equal distance between each of the scale elements. It has the properties of : identity, magnitude and equal distance. The equal distance between scale points helps to know how many units greater than or less than one case is from another. For eg: The meaning of the distance between 25 and 35 is the same as the distance between 65 and 75.

iv.Ratio

It allows for a wide range of both descriptive and inferential statistics to be applied. The factor which clearly defines a ratio scale is that it has a true zero point. The properties of ratio scale are: identity, magnitude, equal distance and absolute zero. These properties allow to apply all possible mathematical operations that include addition, subtraction, multiplication and division. The absolute true zero allow to know how many times is one case greater than another. For eg: height, weight, duration.