Types of Data Visualization: Bar Graph, Histogram and Pictograph - Class

In this module, we will discuss the visualization of data. There are different types of data visualization. The data is represented graphically to give a clear idea of what it represents.

Types of Data Visualization

1. Pictograph
2. Bar Graph
3. Double Bar Graph
4. Histogram

Let us learn different types of data visualization in detail.

We already know about a pictograph. A Pictograph is a Pictorial representation of data using symbols.

Then comes the bar graph. A bar graph is the display of information using bars of uniform width, their heights being proportional to the respective values they represent. Bar heights give the quantity for each category. Bars are of equal width with equal gaps in between them. The bar graph is generally used to represent ungrouped data.

We can interpret the following information from this bar graph.
(i) The maximum number of students in class 8th is in the year 2007 � 08.
(ii) And the minimum numbers of students were in the year 2003 � 04.
(iii) There is an increase in the number of students every year.

Next, we have a Double Bar Graph: A bar graph showing two sets of data simultaneously. It is useful for the comparison of the data.

This graph shows the marks of a student in the year 2005-06 and 2006-07. Here we are comparing the marks of a student in different subjects in 2 sessions.

Next, let's talk about other types of data visualization...

We can also visualize grouped data in the form of histograms. The histogram is a graphical representation of a grouped frequency distribution. It consists of rectangles with classes as a base and the corresponding frequencies as height.

A histogram is constructed from a frequency table. The classes are shown along X-axis or horizontal axis and the respective frequencies along the Y-axis or the vertical axis, using suitable scales on each axis. Bars are of equal width with no gaps in between. This histogram shows the height of girls in class VII.