Data Visualization 101: How to Use Bar, Line and Pie Charts in Your Data Visualizations

October 31, 2018
August 24, 2020

With data analytics playing a larger role in business performance each year, the ability to visualize results has become a useful skill for anyone looking to share the results of their work or anticipate future outcomes.

At Onebridge, our in-depth experience with data analytics means we spend a lot of time developing innovative ways to visualize our clients’ data. Creating reports and dashboards to drive meaningful discussions and provide a solid foundation for decision making is one of our specialties, and key to building an accurate understanding of your data within your team.

Knowing which pitfalls and mistakes to avoid can make your visual reporting more impactful and helpful for your audience. That’s why we put together a Data Visualization 101 e-book—to give you a basic introduction into data visualization tips and tricks to boost your reporting efforts. Below is an excerpt offering an intro to the best and proper uses for the 3 most popular types of visuals—read the rest of Data Visualization 101 here.

Bar Graph

The best use for a bar graph is to display trends grouped by categories or time. One axis shows an amount while the other is used to label each bar. It’s best not to use a bar graph to compare items that require different scales (see the chapter on Scale.) If you need to show percentages that add up to a whole, try a 1OO% bar graph. They are always the same length, and divided by color. This works a little better than pie charts because the eye sees differences in length more easily than it sees differences in area.

To tell more of a visual story and help viewers quickly draw conclusions, always organize the data from highest to lowest or lowest to highest. The only exception is if the axis determines the order of the information.

Pie Chart

We’ll be blunt: most data visualization experts would recommend avoiding pie charts completely because they are frequently misused and can so easily misrepresent the data. Their popularity is high, but their usability is low.

Pie charts are used to depict a part of a whole, creating the common misconception that all percentages can be accurately represented by a pie chart. But a percentage meant to show an increase or decrease from an original number, common in financial reporting, can’t be accurately represented by a pie chart because pie charts do not show change over time and are usually not appropriate for making comparisons. If you can, make sure the name of each category and its value is labeled directly on the pie chart rather than in a key off to the side—this makes it much easier for viewers to quickly glance at the visualization and understand what they need to know.

Line Graph

Line graphs are great for displaying trends over time and across categories. The advantage of a line graph over a bar graph is that it shows trend lines which make understanding change over time easier. Plus, you can show multiple lines to see how trends compare.

It’s best to reserve the line graph for visualizations showing trends and change over time, otherwise they can begin to complicate the message.

A good visualization starts with basic knowledge of the tools available. We hope this data visualization primer helps you get started down the path of improving your data visualization efforts.

At Onebridge, we have experience with a wide variety of data visualization tools. We can partner with you to build your internal data visualization capabilities and augment your team’s data literacy from the inside.  We’d love to meet you and learn more about your goals—contact us now.

Sign-Up for the Onebridge Newsletter

* Indicates required field
Thank you! Your submission has been received! We'll get back to you as soon as possible.
Oops! Something went wrong while submitting the form.
If you would like to be notified of our upcoming events and workshops, please use the form here to sign up for our newsletter.

If you would like Onebridge to conduct training or run a workshop for your organization, please contact us today by clicking here.

You can also follow us on social media to see upcoming events as well as other resources like blogs, eBooks, and more!