Question

Identify two types of variables and four scales of measurement. How they are related with each other? What is the difference between variables and constants? Why do we need to study variables instead of constants in statistics? (Business Statistics & Application Course)

Answer 1

The broad two types of variables are:

Categorical variable - The variable which takes particular values or which are class labels in classification.

Numerical variable - The variable which takes on numerical values either discrete or continuous are called numerical variables.

The 4 scales of measurement are:

Nominal scale - This scale is for categorical variables. There is no ordering of groups. Eg. Gender (male female)

Ordinal scale - This scale is for categorical variables where the values are ordered and the distance between the orders is known.

Interval scale - Interval scale is for numerical variables wherein there is order and difference between two values is known.

Ratio scale - This is for numerical variables. Difference between values is significant. There exists a zero point which is meaningful.

Variables change their values over time whereas constants do not change their values over time.

Statistics is probability, estimation and data. Time is a very important factor here. Researchers are interested in values that change over time. So variables are being studied in statistics.