Bad Data Visualization Examples and How to Fix Them

Jeff Rudolph
14 min readJul 21, 2023

--

Photo by Jakayla Toney on Unsplash

The Art of Seeing: Unveiling the Dark Side of Data Visualization

Picture this: You’re handed a graph that is supposed to shed light on a complex set of data. Yet, as you gaze upon it, confusion settles in. The message is obscured, buried beneath a cacophony of colors, lines, and shapes.

Welcome to the realm of bad data visualization. Data visualization is the process of representing information visually, allowing our brains to quickly grasp patterns and insights that might be hidden within raw data.

When done well, it can be a powerful tool for communication and decision-making. However, when executed poorly, it can lead to more confusion than clarity.

A Clear Lens: Defining Data Visualization

Data visualization is the art and science of presenting complex information in visual form — charts, graphs, infographics — to make it more accessible and understandable. It transforms dry numbers into meaningful visuals that enable us to identify trends or correlations at a glance. Visualizations come in many forms — bar graphs, line charts, scatter plots — and selecting the best way to represent data depends on its nature and intended purpose.

For example:

  • A bar graph might be ideal for comparing market share between different competitors over time.
  • An area chart could effectively display changes in temperature throughout the year.
  • A bubble chart might illustrate the correlation between income levels and educational attainment.

But regardless of which type we choose from this vast array of possibilities, good visualizations share common qualities: simplicity, clarity, accuracy, and an ability to engage viewers in a meaningful way.

The Pitfalls: Common Mistakes in Data Visualization

Even with the best intentions, designers and analysts can fall into the trap of producing bad data visualizations. Some of the most common issues that lead to confusion include:

  • Overcrowded and Cluttered Visuals: when a graph or chart becomes overrun by excessive data points or lacks proper organization, it overwhelms the viewer’s ability to absorb information efficiently.
  • Misleading Visual Representations: manipulating scales, axes, or selectively displaying data can skew interpretations and mislead audiences, intentionally or not.
  • Confusing Chart Choices: selecting inappropriate chart types for specific data sets can result in unclear or misleading visualizations that fail to effectively convey the intended message.
  • Lack of Accessibility and User-Friendliness: neglecting accessibility guidelines for visually impaired users or ignoring factors such as different screen sizes hinders inclusivity and limits usability.

In this article, we will delve into each of these categories in detail, examining real-world examples that highlight the perils of bad data visualization. Prepare to witness a kaleidoscope of misguided charts and graphs that will make you question what you once believed about visualizing information effectively!

Overcrowded and Cluttered Visuals

The Pitfall of Too Many Data Points in a Single Graph or Chart

Data visualization is meant to simplify complex information, but there are times when the desire to include as much data as possible can lead to overcrowded visuals. When a graph or chart becomes overloaded with too many data points, it can quickly become overwhelming and difficult to decipher.

The best intention of including every single piece of information can backfire if it hampers the viewer’s ability to understand the main message. Consider an example where a line chart displays mortality rates across different age groups over several years.

If each data point is represented individually without any filtering or aggregation, it could result in a congested mess of overlapping lines that make it nearly impossible to discern any meaningful trends. In such cases, it’s crucial to prioritize essential data points and remove excessive details that distract from the main story.

Poor Use of Color, Font, and Layout Leading to Confusion

Color, font, and layout are powerful tools in data visualization that can enhance understanding or wreak havoc if used carelessly. Unfortunately, even experienced designers can sometimes fall into the trap of poor choices when it comes to these elements.

Take color, for instance: using too many colors without purpose or employing clashing color combinations can create visual chaos that confuses rather than clarifies. Similarly, font selection plays a significant role in ensuring readability and coherence within a visualization.

If inappropriate fonts are used — ones that are either too small or too ornate — they can impede comprehension and make reading laborious for viewers. Furthermore, an improperly structured layout lacking clear visual cues and hierarchy can leave users lost amidst an unorganized sea of numbers and charts.

Lack of Hierarchy and Organization in Presenting Information

Ineffective hierarchy and organization hinder the viewer’s ability to navigate and interpret data visualizations seamlessly. Imagine a bar chart comparing peak-hour traffic congestion across different cities.

If the bars are not sorted in any particular order or if the axis labels are jumbled, viewers will struggle to quickly identify which city experiences the highest congestion or make valid comparisons between different categories. Moreover, failing to provide clear distinctions between different elements within a visualization can lead to confusion.

A scatter plot that includes data points without proper labeling or grouping loses its usefulness as it becomes nearly impossible to attribute any meaning or context to individual points. Establishing a clear hierarchy, organizing data thoughtfully, and ensuring that visual cues guide viewers’ attention are essential for effective communication through data visualization.

Overcrowded visuals with too many data points, poor use of color, font, and layout choices that confuse rather than assist readers, as well as a lack of hierarchy and organization in presenting information, can all contribute to ineffective data visualization. To avoid these pitfalls, designers must prioritize relevant data while filtering out excessive details for clarity.

Careful consideration of color palettes and fonts is necessary for optimal readability. Additionally, establishing visual cues and organizing information in a logical manner ensures that viewers can easily navigate and comprehend the message conveyed by the visualization.

Misleading Visual Representations

Distorted scales and axes that manipulate perception

Subtitle: Revealing the Deceptive Power of Scaling When it comes to data visualization, the choice of scales and axes can have a profound impact on how information is perceived. Unfortunately, some visualizations intentionally distort these elements to manipulate our understanding.

For example, imagine a line chart where the y-axis starts at a value higher than zero, artificially exaggerating changes in the data. This manipulation can make trends appear more significant than they actually are or falsely create the illusion of drastic shifts over time.

To add to this distortion, skewed numerical scales can also be employed to misrepresent relationships between variables. Imagine an area chart comparing current-account balances between two countries: one with significantly larger figures than the other.

If the areas representing these balances are not properly scaled according to their values, it could mislead viewers into believing that one country holds a much greater economic advantage over its counterpart. Such distortions not only undermine accurate comprehension but also have real-world consequences when decisions are based on flawed perceptions.

Inaccurate or incomplete labeling of data points

Subtitle: The Lost Landmarks in a Data Wilderness Proper labeling is essential for any data visualization as it provides crucial context and helps users understand what they are interpreting.

However, inaccurate or incomplete labeling can lead us astray in our exploration of data insights. Consider a bubble chart mapping out social media engagement rates for various industries without clear labels indicating which bubble represents which industry.

Without this essential information, we find ourselves lost in a sea of bubbles with no way to attribute meaning or identify trends accurately. Moreover, incomplete labeling can occur when critical variables go unmentioned or when legends fail to explain symbols adequately.

These omissions leave viewers grasping for understanding and hinder their ability to extract meaningful insights from the visual representation at hand. In such cases, even the best intentions of the data scientist or designer can fall short, leaving audiences confused and potentially misinformed.

Cherry-picking data to support a biased narrative

Subtitle: The Art of Misdirection: Selective Storytelling Through Visualization While data visualization aims to present information objectively, it is not immune to biases that can arise through cherry-picking.

This practice involves selectively choosing data points or subsets of data that align with a preconceived narrative, often disregarding contradictory evidence. By highlighting specific data points that bolster a particular viewpoint while downplaying or omitting conflicting information, visualizations can subtly sway interpretation in favor of a biased agenda.

For instance, imagine an education-level comparison bar chart where only certain demographic groups are included while others are conveniently excluded. This intentional exclusion skews the viewer’s perception and fosters unjust conclusions based on incomplete information.

When used to support biased narratives, these misleading visual representations not only undermine trust in data but also perpetuate misinformation and hinder progress by obscuring an objective understanding of complex issues. Misleading visual representations in data visualization can take various forms and have far-reaching consequences.

Distorted scales and axes manipulate our perception by exaggerating changes or relationships between variables. Inaccurate or incomplete labeling leaves viewers lost in a sea of unattributed symbols or without essential context.

Cherry-picking data supports biased narratives by selectively presenting information that aligns with predetermined viewpoints while disregarding contradictory evidence. To avoid these pitfalls and ensure accurate understanding, it is crucial to employ appropriate scaling techniques, provide clear labeling for all elements, and prioritize objectivity when making decisions about which data to include in visualizations.

Confusing Chart Choices

The Importance of Choosing the Right Chart Type

When it comes to data visualization, choosing the right chart type is crucial. It’s like selecting the perfect tool for a specific task. However, in the sea of available chart options, it’s easy to make mistakes that lead to confusion and misinterpretation of data.

Choosing Inappropriate Chart Types for the Given Data Set

One common mistake is opting for the wrong type of chart altogether. Imagine trying to represent market share data using a pie chart with too many categories.

The result would be a jumbled mess that fails to convey any meaningful information. In such cases, a better choice might be a horizontal bar graph or stacked column chart, which allows for clear visual comparison.

Mixing Incompatible Chart Types within the Same Visualization

Another pitfall is mixing incompatible chart types within the same visualization. While it may seem like an innovative idea, combining multiple charts without careful consideration can confuse your audience rather than enlighten them. For example, attempting to display time series data with both a line graph and a bubble chart simultaneously could obliterate your message’s clarity.

Failing to Provide Clear Context or Explanation for Complex Charts

Complex charts have their place, especially when dealing with intricate statistical information or detailed analysis. However, presenting these without proper context or explanation can leave viewers scratching their heads in bewilderment. A diligent data analyst must put themselves in their target audience’s shoes and strive to provide clear explanations alongside complex visuals.

This allows users who may not be familiar with certain data visualization techniques to grasp the intended message easily. The world of data visualization offers an array of powerful ways to present information effectively; however, even with the best intentions, mistakes happen along the way.

By avoiding inappropriate chart types for given datasets, refraining from mixing incompatible chart types, and ensuring clear context and explanations are provided for complex charts, and you can mitigate the risk of confusing your audience and foster a better understanding of your data visualization assets. Remember, choosing the right chart type is an art that requires thoughtful consideration and a deep understanding of both your data and your target audience’s needs.

The Importance of Accessibility and User-Friendliness

Ignoring accessibility guidelines for visually impaired users

When it comes to data visualization, ensuring accessibility for all users should be a top priority. Unfortunately, many creators overlook the needs of visually impaired individuals.

By ignoring accessibility guidelines, they inadvertently exclude a significant portion of the population from accessing and understanding the information presented in their visuals. This is a grave disservice because everyone deserves equal access to data insights.

One common oversight is failing to provide alternative text (alt text) for images or graphs. Alt text acts as a textual description that screen readers can read aloud to visually impaired users.

Without alt text, these individuals are left in the dark, unable to comprehend the visual content being shared. Additionally, not using proper headings or labels in HTML markup further hampers screen reader navigation through the data visualization.

Not considering different screen sizes or resolutions

In this era of diverse devices and varying screen sizes, neglecting responsive design can render data visualizations meaningless or even unreadable on certain platforms. Failing to consider different screen resolutions leads to distorted visuals that make interpretation impossible. Imagine viewing a line graph on a mobile device where all the data points are squeezed together due to poor scaling; it’s like trying to decipher hieroglyphics without a Rosetta Stone.

To avoid this issue, designers must prioritize responsive design principles during development. This means adapting visuals intelligently across various devices so that viewers can access and engage with them easily, regardless of whether they’re using a desktop computer or a smartphone.

Failing to provide interactive features or clear navigation options

Interactivity plays an essential role in enhancing user experience within data visualizations; however, many creators fall short in this regard by offering static visuals devoid of any interactive elements or clear navigation options. Even with well-designed charts and graphs, without the ability to interact with the data, users miss out on deeper exploration and personalization. Interactive features such as tooltips that display additional information when hovering over data points, zooming capabilities to examine specific periods or values closely, and filters for selecting different categories or time frames can greatly enhance user-friendliness.

Failure to incorporate these elements limits the utility of data visualizations and reduces their effectiveness in conveying complex information. Accessibility and user-friendliness are crucial aspects of creating effective data visualizations.

Ignoring accessibility guidelines for visually impaired users, not considering different screen sizes or resolutions, and failing to provide interactive features or clear navigation options are common pitfalls that hinder the accessibility and usability of visuals. By addressing these issues, designers can ensure that their data visualizations reach a wider audience while providing an inclusive experience for all users.

Unintuitive Data Presentation Techniques

Using unconventional visual metaphors that hinder understanding

Subtlety and creativity can enhance data visualization, but sometimes unconventional visual metaphors can lead to confusion. When attempting to represent data using unusual symbols or imagery, it is crucial to consider the target audience’s familiarity with those representations.

For instance, if a line chart depicting market share is transformed into a maze-like visual representation with no clear visual context, it becomes challenging for viewers to interpret the information accurately. It is essential to strike a balance between creativity and clarity in order to ensure that the visuals effectively communicate the intended message.

Employing excessive animation or unnecessary visual effects

While adding animation or flashy visual effects may initially seem engaging, overdoing it can distract viewers from the actual data being presented. Excessive animations and unnecessary effects can hinder understanding rather than enhance it.

Subtle animations may help draw attention to important information, but when every element of a chart is animated or when there are constant flashy transitions, the viewer’s focus shifts from comprehending the data to deciphering the various extraneous visual elements. The key here is moderation — using animations sparingly and purposefully.

Presenting complex statistical information without proper simplification

One of the common pitfalls in data visualization lies in presenting complex statistical information without simplifying it appropriately for the target audience. While providing detailed insights and thorough analysis is crucial in certain contexts, overwhelming viewers with too much information at once can result in confusion rather than comprehension. It’s essential to strike a balance between depth and simplicity by offering concise summaries or clear explanations of complex concepts.

Simplification does not imply oversimplifying or withholding vital details; rather, it involves organizing information in a logical manner that guides viewers through their understanding of complex charts or graphs. Unintuitive data presentation techniques can hinder the effectiveness of data visualization.

Using unconventional visual metaphors without considering their familiarity to the target audience can lead to confusion. Employing excessive animation or visual effects may distract viewers from the actual data, so moderation is key.

Presenting complex statistical information without proper simplification can overwhelm viewers and hinder comprehension. By understanding these pitfalls, we can strive for more intuitive and effective data visualization that truly communicates insights to audiences in a clear and accessible manner.

Cultural Insensitivity in Data Visualization

Inappropriate use of symbols, colors, or imagery across cultures

Data visualization is a powerful way to communicate information effectively, but it can also inadvertently perpetuate cultural insensitivity if not handled with care. One common mistake is the inappropriate use of symbols, colors, or imagery across cultures. For example, using a symbol that holds deep significance in one culture and applying it without consideration to another culture can be offensive or misleading.

Similarly, certain colors may have different meanings in different cultures; using them without understanding their cultural associations can result in confusion or offense. It is crucial for data visualizers to be conscious of these potential pitfalls and aim for inclusivity in their designs.

Neglecting cultural nuances when interpreting data visuals

Interpreting data visuals requires an understanding of not only the numbers and patterns but also the cultural nuances that might influence how people perceive the information. Neglecting these nuances can lead to miscommunications and misunderstandings.

For instance, a graph showing rising temperatures over time may seem alarming at first glance, but when considering historical climate patterns specific to a region, it might not be as concerning as initially thought. By recognizing the impact of cultural context on data interpretation, we can avoid misrepresenting information and ensure more accurate understandings.

Reinforcing stereotypes through biased representation

Data visualization has the potential to reinforce stereotypes if creators rely on biased representations without critically examining their choices. By presenting data selectively or manipulating visual elements such as chart scales or sizes based on personal biases or preconceived notions about certain groups of people, creators risk perpetuating harmful narratives. This can further marginalize already vulnerable communities and hinder progress towards equity and inclusion.

It is essential for data visualizers to approach their work with empathy and strive for fairness by accurately representing diverse experiences rather than reinforcing stereotypes. Cultural sensitivity plays a vital role in data visualization.

To avoid cultural insensitivity, creators must be mindful of the symbols, colors, and imagery they use across different cultures. They should also consider cultural nuances when interpreting data visuals to ensure accurate understanding.

Furthermore, it is crucial to avoid reinforcing stereotypes through biased representation that can perpetuate harmful narratives. By taking these considerations into account, data visualizers can create inclusive and impactful visualizations that foster understanding and promote positive change.

Case Studies: Notorious Examples of Bad Data Visualization

The “Napoleon’s March” infographic by Charles Joseph

Subtitle: When Artistic Ambition Overpowers Clarity One infamous example of bad data visualization is the “Napoleon’s March” infographic created by Charles Joseph Minard in 1869. While often celebrated as a masterpiece of design, this visualization suffers from several critical flaws.

The intention was to depict Napoleon’s ill-fated Russian campaign, including troop numbers, temperature, and geographical locations. However, the execution falls short.

Firstly, the use of different sizes and shapes to represent troops and their losses becomes confusing rather than informative. The thick line indicating the retreat path dominates the visual, making it difficult to discern individual troop movements.

Additionally, the lack of clear labels for dates and locations makes it challenging to track the progression accurately. Furthermore, Minard chose to incorporate multiple variables on a single chart with different scales and shades — a decision that muddles comprehension.

By superimposing temperature data on the lower part of the graph using an unfamiliar scale (Réaumur), he adds unnecessary complexity that detracts from understanding essential aspects of Napoleon’s campaign. While “Napoleon’s March” may be hailed as a masterpiece in artistic terms, it fails as an effective data visualization due to its lack of clarity and confusing design choices.

It serves as a reminder that even with the best intentions and artistic flair, good data visualization requires careful consideration of appropriate chart types, clear labeling, intuitive design elements, and simplicity for optimal comprehension. (Note: This is just one example; there are numerous other infamous instances that could be explored in detail.)

Conclusion

In our data-driven world, where accurate interpretation holds significant value for decision-making processes across industries like finance or healthcare, it is crucial to recognize the importance of good data visualization. While bad data visualization examples may be plentiful, they serve as valuable lessons on what not to do. By avoiding overcrowded visuals, misleading representations, confusing chart choices, lack of accessibility and user-friendliness, unintuitive presentation techniques, and cultural insensitivity, we can ensure that information is communicated clearly and effectively.

The power of good data visualization lies in its ability to simplify complex data analysis and present it in a visually appealing and easily comprehensible manner. So let us embrace the best tools available to us, research different chart types suitable for our data sets, adhere to accessibility guidelines for all users, simplify complex charts where necessary, and respect cultural nuances when interpreting visual representations.

By doing so, we can transform bad charts into good ones and enhance our ability to communicate insights with precision. Remember: With the right approach and a commitment to continuous improvement in our data visualizations, we can create a future where clarity reigns supreme and decision-makers are empowered by the beauty of well-presented information.

--

--

Jeff Rudolph

I’m a science and technology writer which might interest you, and an aspiring novelist which won’t.