By Kanza Khan
VARIABLES
A variable is any characteristic, number, or quantity that can be measured or counted. A variable is also called a data item. Examples of variables are age, gender, country of birth.
There are two types of Variables: Numeric and Categorical.
A numeric variable describes a measurable quantity. Examples are heart rate and test scores.
Numeric can further be divided into two parts: Continuous and Discrete.
A continuous variable can take any value between a set of real numbers. Examples are age, height, temperature.
A discrete variable can take any value between set of whole values. It cannot take the value of a fraction. Examples are number of senior citizens in a family or number of registered vehicles.
A categorical variable describes the quality of a data set. These are also known as qualitative variables. Examples are hair colour, race, educational level.
There are two types of categorical variables: Ordinal and Nominal.
Ordinal variables comprise of values that can be logically ranked for instance, academic grades such A,B,C or clothing size such as small, medium, large.
Nominal variables comprise of values that cannot be organised in any logical sequence for instance, religion and eye color.