Insightful Visualizations that Compare Numbers

Effective Examples of Visualization for Comparison

Whether the visualization is employed to compare numbers or highlight trends between different groups of data, it is a powerful tool for communicating a clear and concise story of the data. The following sections will demonstrate some of the most effective forms these visualizations can utilize. 

Bar/Column Chart 

These types of charts are the simplest yet effective visualization technique for comparing numbers by representing the values and categories of data through vertically or horizontally oriented rectangular bars. Utilizing the x-axis to define the categories and the numerical values on the y-axis, with the length of the bars serving as a quick means of analysing the disparity or commonality between the categories. For instance, the chart below identifies the common items purchased for Valentine's and illustrates the percentage of how much people spent on these categories in 2022. With chocolate and other food-related Valentine gifts taking the lead. 

Bar Chart Example

Side-by-Side Chart

Expanding upon the bar or column charts, a Side-by-Side graph uses the same bars to represent the value of each category; instead, this graph pairs individual bars together that each represent specific subcategories within the same group to better showcase at a glance the differences between the bars. However, it is best to use at most two category groups; otherwise, the graph can become cluttered and difficult to read. For example, this Side-by-Side chart highlights the differences between Male and Female students by late excuses, noting overslept being the most common excuse by Males that nearly dwarfs the number of female students using the same excuse. 

Side-by-Side Chart

Line Charts

Instead of bars or columns, line charts utilize dots on a graph to represent a series of data points connected through a single or multiple lines. For the comparison of numbers, the path created by the interconnected data points helps to highlight the patterns or trends of the data, showcasing instances of growth, stagnation, consistency, or a drop in value for the categories. Most commonly seen in financial or economic industries, for example, these help illustrate the rise or fall of figures in the Stock Market. As demonstrated in the example below, this line chart showcases the steady growth of Meta's (formerly known as Facebook) annual revenue across its platforms from 2010 to 2022. Reaching the highest point in 2022 at around $120,000. 

Line Chart Example

Slope Graph

Almost a simplified version of a line chart, a slope graph typically employs two data points on parallel vertical axes connected by a line to visually track multiple categories in different scenarios or quantitative values to highlight changes over time or numerical ranking. As shown in this example, the slopegraph demonstrates fruit sales in tons between 2010 and 2022, highlighting orange with the lowest sales over the year compared to the other top-selling fruits. 

Slopegraph Example

Conclusion

Regardless of the visuals you use for comparing numerical values, it is best to first understand the message or story behind the data that you want to communicate to the intended audience. By doing so, the data will be more effectively represented in a format that provides the most readability and clarity.

REFERENCES

7 Types of Comparison Charts for Effective Data Visualization

24 types of charts and graphs for data visualization

Slopegraphs : A comprehensive guide 

Side-By-Side Bar Chart: Pinpoint Insights in a Snap

VHS Learning (Side-by-Side Example)