Continuous variables: A variable which has an infinite number of possible values or whose values can be measured is referred to as continuous variables. For reference, a continuous variable can take values between 1 – 2 that is 1.02, 1.08. Example income, weight, age, height etc.
Quantitative variables: Variables which are measured on the numeric and quantitative scale are referred to as quantitative variables. Variables measured on ordinal, interval and ratio scale of measurements are quantitative variables. For example height, weight, age etc.
Qualitative variables: Variables that are not numerical but are categorical in nature are qualitative variables. Variables measured on a binary and nominal scale of measurement are qualitative variables. for example gender, eye color, religion etc.
Nominal scale of measurement: This includes variables that are categorical in nature. Example Gender, location, religion and Favorite Color.
Ordinal scale of measurement: These are the variables that can be ordered or ranked in some order of importance. Example Quality of product, Satisfactory Level is measured on the ordinal scale of measurement.
Interval scale of measurement: Variables which have equal differences between scale values and equal quantitative meaning are measured on an interval scale of measurement. It does not have a true zero point. A true zero point means that a value of zero on the scale represents zero quantity of the construct being assessed. Example Temperature. Zero degrees Celsius doesn’t mean there is absolutely no heat present in the environment.
Ratio scale of measurement: These variables have equal differences between scale values and equal quantitative meaning. They also have a true zero point. A true zero point means that a value of zero on the scale represents zero quantity of the construct being assessed. Example Height and Weight of a person is a measured on ratio scale of measurement. It is suitable to say that a person of height 8” is twice as tall as a person with height 4” inches and a person with weight 60 kg is twice as heavy as a person with weight 30 kg.