Creating a data visualization is just a beginning. The true test of its value lies in how well it communicates your insights. A great data visualization doesn’t just look polished — it delivers a clear message, grabs attention, and ensures the audience walks away with the right message.
But how can you be sure your visual is ready? By putting it through three essential tests. These are the same tests I use on my data visualizations, and they’re designed to help analysts refine their work, eliminate confusion, and deliver visuals that resonate.
1. The Spartan Test: Less Is Always More
Data visualizations often suffer from a common problem: clutter. Extraneous gridlines, unnecessary labels, distracting colors—these elements don’t just crowd your graphic; they actively detract from the clarity of your message.
The Spartan Test is about ruthlessly evaluating every element in your visualization to ensure it earns its place.
How to Run the Spartan Test:
Examine every part of your graphic — titles, legends, labels, gridlines, annotations. Ask yourself:
- Does this element contribute to the insight?
- Would the story change if I removed it?
If the answer is no, delete it. Don’t hesitate.
Keep the mantra “less is more” front and center. Every element you remove strengthens the focus of your visual and builds trust with your audience by delivering exactly what they need—and nothing they don’t.
Why It Works: Cluttered visuals can overwhelm viewers and obscure your key message. The Spartan Test ensures your graphic is clean, focused, and impossible to misinterpret.
Example: Visualize a bar graph with rigid lines, labels for each data point on every bar, a main heading, a subheading, a key, and unnecessary use of colors. If we were to remove half of these elements, would the message be easier to understand? Most likely, it would.
2. The Peek Test: Direct Attention to What Matters
Your audience won’t spend hours studying your visual. In reality, you only have a few seconds to capture their attention and direct it to the most critical insight. The Peek Test ensures your visual’s use of eye-catching contrast to focus the audience’s attention aligns with your intention.
How to Run the Peek Test:
- Step away from your graphic for a moment. If it’s on paper, turn it over; if it’s on-screen, switch to another application or take a short walk.
- Return to the visual and give yourself just five seconds to glance at it. Ask yourself: Where is my eye drawn first?
- Is this the insight I want my audience to focus on?
When your gaze falls on an element that doesn’t contribute to the overall message, such as an out-of-place title, a disproportionately large legend, or a distracting data point, it’s necessary to make some adjustments. Utilizing techniques like color, size, and placement can draw attention to the most important elements of your presentation
Why It Works: The human brain is wired to pay attention to contrast through preattentive attributes, like color, size, and shapes. By using the Peek Test, you can control where your audience’s attention goes.
Example: If you’re displaying a line graph that highlights quarterly sales, it’s important for the viewer’s eye to be drawn to the significant increase in Q4. If they are instead distracted by — say — a decorative background, you have missed your goal. To refocus their attention, try adjusting the use of contrast by bolding the Q4 line so it stands out more prominently.
3. The Colleague Test: The Ultimate Reality Check
Even when you think your visual is perfect, it’s easy to overlook blind spots. That’s where the Colleague Test comes in. By sharing your work with someone who has no prior knowledge about your project, you can confirm that your visual effectively conveys the intended message.
How to Run the Colleague Test: Find a colleague who hasn’t been involved in your analysis or design process. Give them minimal context — ideally none. Simply show them your visual and ask:
- What’s the main message you see here?
- How does the graphic support that point?
- What questions does this graphic raise for you?
Pay close attention to their feedback. If their interpretation matches your intended message, you’ve succeeded. If not, go back and revise the visual until the takeaway is clear.
Why It Works: Your audience won’t have the same depth of knowledge you do. The Colleague Test replicates this dynamic, revealing whether your visualization is intuitive or requires further refinement.
Example: If your colleague misunderstands a pie chart showing market share — perhaps interpreting the colors as product categories rather than competitors — it’s a sign the design needs reworking.
Why These Tests Matter
A data visualization isn’t just a static graphic; it’s a living, evolving tool for communication. Running these three tests ensures your visuals aren’t just attractive but is also:
- Refined and distraction-free (Spartan Test)
- Using contrast in an effective way (Peek Test)
- Understandable and clear (Colleague Test)
When your visuals pass these tests, they don’t just inform—they captivate, clarify, and inspire action.
Your Challenge
The next time you create a data visualization, don’t stop at the design phase. Put your graphic through the Spartan, Peek, and Colleague Tests. Adjust until it passes all three with flying colors.
