This is how a type of graph is known in which the variations of a phenomenon or the links that the parts of a set have are shown, for which it offers very specific information in a simplified and schematic way. It is a different way of summarizing information and interpreting it visually, and it should be noted that there are different types of diagrams, which are used depending on the need for communication or the object of study.
This time we are going to focus on the bar chart, which is defined as the 2D representation of a quantitative or qualitative variable through horizontal or vertical columns, bearing in mind that changing the axis is simply a matter of design.
Bar chart example 1
The boss of a company asks his workers a question: When do you prefer to enjoy your vacations ? Of course, they have to choose between 4 fortnights. The answer comes from 224 workers of the company.
To better see the data, below we are going to show a vertical bar chart in which you can see how many of them opt for the month of August, more specifically for the first fortnight.
Bar chart example 2
The following bar chart counts the grades of the students of a 1st ESO class. From it we are going to fill in certain questions.
- How many students are in the class? There are 29 students.
- What grade is the most common among all students? The good.
- How many students have not passed the subject? 3 students.
- How many students have passed the course? 26 students.
Bar chart example 3
In this case we are going to present an example of a stacked bar chart. But what is it? This is the graphic representation of two or more series or grouping of data, but the bars that show the frequencies of each variable are stacked one on top of the other.
The use of it is to show how a much larger category can be divided into much smaller categories to compare the different values with respect to the total, although it also serves to compare each other.
Example of a bar chart for discrete quantitative variables
When a discrete variable is represented, the bar chart is used to make a differential graph. It is recommended that the bars be thin enough to show that the data taken by the variable is discrete.
An example that we are going to show you is the number of inhabitants per dwelling in the Basque Country (these are not objective data). The variable number of inhabitants is quantitative, so we can order the modalities to obtain greater clarity.
|NUMBER OF RESIDENTS||ACCUMULATED HOMES|
|10 or more people||2,418,133|