Types of Graphs & Charts

When dealing with numbers in statistics, incorporating data visualization is integral to creating a readable and understandable summary of a dataset. It doesn’t matter if it’s a large or small dataset, visualizing data using graphs and charts will contribute largely to your audience understanding the message.

There are, however, numerous types of graphs and charts used in data visualization and it is sometimes tricky choosing which type is best for your business or data. Each of these graphs has its own strengths and weaknesses that make it better than others in some situations.

You may need to visualize the outcome of scientific research, a sales report, an industry infographic, or a pitch deck demographic. Graphs and charts are easy ways of showcasing each of these content.

What is a Graph?

A graph is a pictorial representation of data in an organized manner. Graphs are usually formed from various data points, which represent the relationship between two or more things.

A picture says a thousand words, they say. A graph, on the other hand, not only says a thousand words but also tells a million stories.

Each point, stroke, color, or shape on a graph has a different meaning that helps in interpreting a graph. They are of different types and vary in structure, with some having just points, others have points joined together by lines, and so on.

Graphs and Charts – What is the Difference?

Although sometimes used interchangeably, it is important to note that there is a difference between graphs and charts. Summarily, we can say that all graphs are charts but not all charts are graphs.

A graph is a  mathematical diagram that depicts the relationship between two or more sets of numerical data over a period of time. Basic data is mainly 2-dimensional with a focus on raw data represented through lines, curves, etc.

Charts, on the other hand, is a representation of datasets with the intent of making the user understand the information in a better manner. Graphs are a good example of charts used for data visualization.

Types of Graphs and Charts

There are various types of graphs and charts used in data visualization. However, in this article, we’ll be covering the top 11 types that are used to visualize business data.

Bar Chart/Graph

A bar chart is a graph represented by spaced rectangular bars that describe the data points in a set of data. It is usually used to plot discrete and categorical data.

The horizontal axis of the chart represents categorical data while the vertical axis of the chart defines discrete data. Although the rectangular bars in a bar chart are mostly placed vertically, they can also be horizontal.

The graph may ascend, descend, or do both depending on what kind of data is being visualized. When studying the relationship between price and supply, it goes down and for peace and demand, it goes up.

When constructing a line chart, you may decide to include the data points or not.

Types of Line Graph

• Simple Line Graph

In a simple line graph, only one line is plotted on the graph. One of the axes defines the independent variables while the other axis contains dependent variables.

• Multiple Line Graph

Multiple line graphs contain two or more lines representing more than one variable in a dataset. This type of graph can be used to study two or more variables over the same period of time.

• Compound Line Graph

A compound line graph is an extension of the simple line graph, which is used when dealing with different groups of data from a larger dataset. Each line in a compound line graph is shaded downwards to the x-axis.

In a compound line graph, each group of data represented by a simple line graph is stacked upon one another.

Uses of a Line Graph

• It helps in studying data trends over a period of time.
• They are easy to read and plot.

Disadvantages of a Line Graph

• It can only be used to visualize data over a short period of time.
• It is not convenient to plot when dealing with fractions and decimals

Histogram Chart

Histogram chart visualizes the frequency of discrete and continuous data in a dataset using joined rectangular bars. Each rectangular bar defines the number of elements that fall into a predefined class interval.

Types of Histogram Chart

The histogram chart is classified into different parts depending on their distribution

• Normal Distribution

A normally distributed histogram chart is usually bell-shaped. As the name suggests, this distribution is normal and is the standard for how a normal histogram chart should look like.

• Bimodal Distribution

In a bimodally distributed histogram chart, we have two groups of histogram charts that are of normal distribution. It is formed as a result of combining two processes in a dataset.

• Skewed Distribution

This is an asymmetric graph with an off-center pick usually tending towards the end of the graph. A histogram chart can be said to be right or left-skewed depending on the direction where the peak tends towards.

• Random Distribution

This type of histogram chart does not have a regular pattern. It produces multiple peaks and can also be called a multimodal distribution.

• Edge Peak Distribution

This distribution has a structure that is similar to that of a normal distribution with a large peak at one of its edges being the distinguishing factor.

• Comb Distribution

The comb distribution has a “comb-like” structure, where the rectangular bars alternate between tall and short.

Uses of Histogram Chart

• It helps in visualizing large amounts of data.
• It reveals the variation, centering, and distribution of the data.

Cons

• It does not visualize the exact values in a dataset.
• It only visualizes continuous data.

Area Chart 

Area charts are used to collectively measure data trends over a period of time by coloring the area between the line segment and the x-axis. In simpler terms, an area chart is an extension of the line chart.

Types of Area Chart

• Simple area Chart

In a simple area chart, the colored segments overlap each other in the chart area. They are placed above each other such that they intersect.

• Stacked Area Chart

In a stacked area chart, the colored segments are stacked on top of one another so that they do not intersect.

• 100% Stacked area Chart

This is a type of stacked area chart where the area occupied by each group of data on the chart is measured as a percentage of its amount from the total data. The vertical axis usually totals a hundred percent.

• 3-D Area Chart

This is the type of area chart measured on a 3-dimensional space.

Uses of Area Chart

• It is visually appealing.
• It gives a clear comparison of different groups of data.

Cons

• It may be difficult to read when compared to other data types.

Dot Graph or Plot

A dot plot is a type of graph with data points, which are vertically represented by dot-like markers. It is said to be similar to the histogram chart and bar chart because the height of the aggregation of each group of the dot-like markers is equal to the frequency of the elements in a particular class interval.

Types of Dot Plot

• The Wilkinson Dot Plot

This type of dot plot uses the local displacement to prevent the dots on the plot from overlapping. This dot lot was created by Leland Wilkinson.

• Cleaveland Dot Plot

This is a scatterplot-like chart that displays data vertically in one dimension. It was developed by William Cleaveland.

Pros

• They are usually very colorful and visually appealing.

Cons

• The data points clutter and become unreadable when dealing with large datasets.
• It is usually difficult to read frequency from the chart

Scatter Plot

Scatter plots are charts used to visualize random variables with dot-like markers that represent each data point. These markers are usually scattered across the chart area of the plot.

Types of Scatter Plot

Scatter plots are grouped into different types according to the correlation of the data points. These correlation types are highlighted below

• Positive Correlation

Two groups of data visualized on a scatter plot are said to be positively correlated if an increase in one implies an increase in the other. A scatter plot diagram can be said to have a high or low positive correlation.

• Negative Correlation

Two groups of data visualized on a scatter plot are said to be negatively correlated if an increase in one implies a decrease in the other A scatter plot diagram can be said to have a high or low negative correlation.

• No Correlation

Two groups of data visualized on a scatter plot are said to have no correlation if there is no clear correlation between them.

Pros 

• It clearly shows data spread
• Ir is usually colorful and visually appealing

Cons

• It cannot give the exact extent of correlation.
• It can only be used to study the relationship between 2 variables.

Bubble Chart

A bubble chart is a multivariable graph that uses bubbles to represent data points in 3 dimensions. It represents data points with bubbles, with the first two variables determining the location of the bubble on the x and y-axis while the 3rd variable determines the size of the bubble.

Types of Bubble Chart

Bubble Charts are divided into different parts according to the number of variables in the dataset, type of data it visualizes, and he number of dimension the graph is.

• Simple Bubble Chart

The simple bubble chart is the most basic type of bubble chart and is equivalent to the normal bubble chart.

• Labeled Bubble Chart

The bubbles on a labeled bubble chart are usually labeled for easy identification, particularly when dealing with different groups of data.

• Multivariable Bubble Chart

In a multivariable bubble chart, the variables in the dataset are usually more than 3 (particularly 4). Therefore, the fourth variable is usually distinguished with color.

• Map Bubble Chart

A map bubble chart is usually used to illustrate data on a map.

• 3D Bubble Chart

This is a bubble chart designed on a 3-dimensional space. The bubbles on a 3D bubble Chart are spherical.

Uses of Bubble Chart

• It can visualize up to 4-dimensional data.
• It is visually appealing

Cons

• It is not good for visualizing large data.
• It may be difficult to ascertain specific values at a glance.

Pictogram Graph

A pictogram graph uses pictures or icons to visualize a small dataset of discrete data. In a pictogram, the icon represents a predefined unit and describes the frequency of the variables in the dataset.

Pros

• It is great for finding weight.

Cons

• The data between points cannot be determined.

Radar Chart

A radar chart is a graphical method used for displaying multivariate data in the form of a two-dimensional chart of three or more quantitative variables represented on axes starting from the same point. (Source: Wikipedia). It is also called the spider graph.