Statistics

What are Categorical data?

Qualitative variables measure attributes that can be given only as a property of the variables. The political affiliation of a person, nationality of a person, the favorite color of a person, and the blood group of a patient can only be measured using qualitative attributes of each variable. Often these variables have limited number of possibilities and assume only one of the possible outcomes; i.e. the value is one of the given categories. Therefore, these are commonly known as categorical variables. These possible values can be numbers, letters, names, or any symbol.

What are Quantitative data?

Quantitative variable records the attributes that can be measured by a magnitude or size; i.e., quantifiable. Variables measuring temperature, weight, mass or the height of a person or the annual income of a household are quantitative variables. Not only all the values of these variables are numbers, but each number gives a sense of value too. Variable refers to the quantity that changes its value, which can be measured. It is of two types, i.e. discrete or continuous variable. The former refers to the one that has a certain number of values, while the latter implies the one that can take any value between a given range.

The term discrete implies distinct or separate. So, discrete data refers to the type of quantitative data that relies on counts. It contains only finite values, whose subdivision is not possible. For example, Number of students in the school, number of people in olimpico stadium.

Continuous data, on the other hand, is described as an unbroken set of observations; that can be measured on a scale. It can take any numeric value, within a finite or infinite range of possible value. For Example, Age, height or weight of a person, time taken to complete a task,etc.

For the graphical representation of continuous data, we use histograms. On the other hand, for the graphical representation of discrete data we use bar graphs.