Bad Visualization Examples, and why They are Bad
“Data don’t lie”, people say. Data has been an important pillar of human history, and it helps us to discover the past, understand the contemporary, and predict the future. Pure data, collected by many means, are believed to be true and accountable. However, they are difficult to gain insights from, especially for the general public. Data visualizations give a solution to this problem.
Starting to become relevant much later than data, visualizations made appearances in around 16th century[1]. Throughout the years, data visualizations have evolved much, and are much more integrated in our daily lives now. However, misuse of visualizations by the media and governments bring confusion, sometimes propaganda, to the information receiver. They are of many forms that not only include charts. Though, today we will see how bad charts make it hard for the general public to objectively absorb information.
Not Starting at “0”
This is a frequently seen and purposely made mistake. As shown in the two figures below, noticeable difference in the information they convey exists.
Although using same data, there is a significant difference in these two bar charts. In the first chart, Student 2 has a bar about 0.5 times higher than Student 1, agree with the level of difference in their data. However, in the second chart, when bar chart starts from 20, the difference between bar heights is greatly enlarged. Now Student 2 has a bar more than doubling the height of Student 1's.
This characteristics is well known and used by the media to convey misleading information. In the Image shown above, a bar chart is used to visualize some U.S. Border Patrol data. We notice that the year of 2013 has a larger number than 2011, about 16 percentage of difference. Nevertheless, this chart is drawn to show a more-than-tripling difference between these numbers. When the general public use solely this chart to summarize information, they are successfully fouled by the media.
Using Wrong Type of Charts
This is less frequently noticed in our daily lives because they just look so unneutral. I will demonstrate with an ABC News’ example.
It is a general knowledge that to use a pie chart, all categories must add up to 100 percent. Otherwise, their data would not even form a circle. Apparently ABC news knows this, but they still wanted to create some confusion. If I solely look at the chart but not the numbers, I would think there’s about one third of people are worrying about getting COVID-19. There are also one third of people are worrying about their family getting it. Are these the truth? Apparently not. In fact, about two thirds of people are worrying about each of these, double from what we are being informed by the chart. Reason behind this is that these numbers does not add up to 100 percent at all. Using a pie chart in this situation is clearly misleading and inappropriate.
Conclusion
In conclusion, misuse of data visualization is now a known issue, and a tool the media uses to manipulate our reception of data. More caution is needed by us when reading these visualizations.
References
[1] Wadhwa, B. Information Visualization, Introduction to the topic of Information Visualization (2022).
[2] Agrawal, M. What Happens When Bar Charts Don’t Start With Zero? https://medium.com/loud-updates/what-happens-when-bar-charts-dont-start-with-zero-7db04221417e#:~:text=When%20a%20bar%20chart%20does,too%20big%20or%20too%20small, 2022.
[3] Jurng, D. Real-life Examples of Misleading Visualizations. https://medium.com/@downyj/real-life-examples-of-misleading-visualizations-8ba9eeba4b8c, 2022.
[4] Mccready, R.
5 Ways Writers Use Misleading Graphs To Manipulate You [INFOGRAPHIC]. https://venngage.com/blog/misleading-graphs/, 2022.
