Types of Diagrams

In general, the statistical data is presented in two forms viz statements and tables. However, there is one more method that represents data i.e. Diagrams. These are attractive way of presenting relevant data and helps people to understand the data quickly. There are a number of diagrams that represent statistical data. Various types of diagrams that are meant to describe data sets are categorized as under:

Types of Diagrams

  1. One-dimensional diagrams like histograms, frequency polygons, and pie charts.
  2. Two-dimensional diagrams like rectangles, squares, or circles.
  3. Three-dimensional diagrams like cylinders, cubes, spheres, blocks, etc.

One Dimensional Diagram

These diagrams are not just simple but most commonly used to present frequency distribution. We prepare them on the basis of a single dimension which is the length. Such diagrams take shape of bars. Although these bars resemble a rectangle, they are not rectangles.

Types of One-Dimensional Diagrams

Line Diagram


In these diagrams, we represent different values through the length of lines. They can be drawn horizontally or vertically. There is an equal gap between different lines. We can make a comparison of the values of different items with the help of the length of the lines. Such diagrams are used when there is a large number of items.

Simple Bar Diagram


In this, the bar is drawn to indicate the single value of a given variable. The bar length depends on the ratio of the magnitude of the given data. It is constructed in two cases:

  • When the data show different values of the variable over a period of time.
  • When the data shows different situations.
  • Both vertical or horizontal bars can be prepared. Also, the gaps between various bars is the same.
Multiple Bar Diagram


A type of one-dimensional diagram wherein there are two or more bars next to each other are drawn. It shows:

  • Values of different variables or
  • Values of different components of the same variable

Just like a simple bar diagram, the gap left amidst the bars of different sets is the same. This is helpful in making the comparison of the values relating to different variables in a set and a comparison of the values of the same variable over of given period of time.

Sub-divided bar diagram


A type of bar diagram in which one bar is drawn for the whole value of a variable. Then the bar is further divided in the proportion to the values of different components of that variable. In a nutshell, values of different components are taken together for drawing this bar diagram and the bar is then classified at the cumulated points.

Duo-Directional Bar Diagram


These diagrams are used to represent the aggregate of two components. Of which one is indicated above X-axis while the other one is shown below X-axis. When these two components are combined together, the total value will be reached.

Two Dimensional Diagram

Those diagrams are based on two dimensions i.e. length and width. Because the product of length and width represents the area, such diagrams are also called Area Diagram.

Types of Two Dimensional Diagrams

Rectangle Diagrams


As said above, rectangle diagrams are created using two dimensions, wherein the first variable is the length and the second one is the width.

Sub-divided Rectangle Diagram


In this diagram one rectangle is drawn to represent the total value of the variable. After that, this rectangle is further split in the proportion to the values of different elements of that variable.

Square Diagram


We cannot use a rectangular diagram when the values of the items greatly vary. this is because if we use a rectangle then one of the rectangles would be having extraordinarily large width than the others. So, we draw squares diagrams for which the square root of the value of an item is determined, and by choosing the suitable scale we draw square.

Circle Diagrams


In this, first, we will create the circle and then we will determine the radius of that circle. We will follow the minimum square root value of the variable to ascertain the radius. In case multiple circles are created in one diagram, then the bases of all circles will lie on the same line.

Pie Diagram


It is circular in shape and the area is split proportionately among different components of the specified variable. It must be noted that the total number of parts of the circle will be equal to the components of the variable. We divide the circle by drawing straight lines from the center to the circumference.

Three Dimensional Diagram

Using three-dimensional diagrams, we indicate the values of different items by the volume of a cube, sphere, cylinder, etc. We use such diagrams at the time of large variations in the magnitude of observations.

Types of Three-Dimensional Diagrams



Representation of numerical figures using pictures, then the diagram is called pictogram. They look really attractive but they are difficult to create.



The alternative term for a cartogram is a map diagram. By using a map diagram we can represent data related to a country or geographical area. They are meant to represent types of characteristics such as:

  • Density of population,
  • Crop yield,
  • Amount of rainfall

Wrap Up

We can choose a suitable diagram by taking into account the nature of the data, the purpose for will the diagram is drawn and the interpretation ability of the audience who is going to view that diagram.

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