A data analyst’s guide to making informative charts

Charts are one of the most powerful tools in data analysis. They help transform raw numbers into visuals that tell a story, highlight trends, and make patterns easy to understand. But not all charts are created equal. A poorly designed chart can confuse the audience, obscure important insights, or even mislead.

Here’s a practical guide to making charts that are informative, readable, and concise—the kind of charts that bring clarity, not clutter.

1. Start With the Question You Want to Answer

Before choosing a chart type or adjusting design elements, ask:

• What do I want my audience to learn from this chart?

• What’s the single most important insight I want them to see?

Every design choice—chart type, colors, labels—should support that goal. A chart that tries to do too much risks overwhelming viewers.

2. Choose the Right Chart Type

Choosing the right chart type is essential. The wrong chart type can distort your message. Use common, well-understood chart types for clarity:

• Line charts → Show trends over time

• Bar charts → Compare categories

• Column charts → Show differences across groups

• Scatter plots → Explore relationships between variables

• Pie charts → Show proportions (use sparingly, and only for a small number of categories)

If in doubt, keep it simple. Readers are more likely to trust a straightforward bar or line chart than a flashy but confusing alternative.

3. Keep It Simple and Focused

Good charts don’t include every possible data point—they highlight the most relevant information.

• Remove unnecessary gridlines, borders, or 3D effects.

• Limit the number of categories or series on a single chart.

• Avoid “chart junk” (decorations that don’t add meaning).

The goal isn’t to show everything—it’s to show the most important thing.

4. Use Color With Intention

Color is powerful, but misuse can overwhelm or distract.

• Use consistent colors for categories across charts.

• Reserve bright or bold colors to highlight the key data point.

• Stick to a limited palette (2–4 colors) for clarity.

• Make sure your chart is readable in grayscale for accessibility.

Example: If you’re highlighting one trend in a line chart, make that line bold and in a stronger color while keeping other lines muted.

5. Label Clearly and Directly

Don’t make your audience work to understand your chart.

• Use clear axis labels with units (e.g., “Revenue ($M)” not just “Revenue”).

• Provide direct labels on the chart when possible instead of relying on legends.

• Keep titles short and descriptive: “Canadian Housing Prices Rose 20% in 2024” is better than “Housing Market Data.”

Good labeling eliminates guesswork and keeps attention on the insight.

6. Make Data Scales Honest and Accurate

Misleading scales can distort meaning, even unintentionally.

• Start axes at zero for bar charts.

• Avoid distorting proportions (e.g., making small differences look huge).

• If you must truncate or zoom in, clearly indicate it (e.g., with a break in the axis).

Your chart should clarify reality, not exaggerate it.

7. Consider Your Audience

Charts should be designed with the viewer in mind:

• For technical audiences, include precise scales, legends, and detailed notes.

• For general audiences, simplify, reduce clutter, and focus on the headline insight.

Think of your chart as a bridge between your analysis and your audience’s understanding.

8. Tell a Story

A good chart isn’t just a picture of data—it’s a step in a larger narrative.

Ask yourself: What’s the story this chart tells?

For example:

• Instead of a plain bar chart of “Annual Sales by Region,” highlight the region that drove the most growth and make that the focus.

• Instead of a trend line that ends abruptly, add a note about why the trend matters or what might happen next.

Charts work best when they fit into a story, not when they stand alone.

9. Test Your Chart

Before publishing or presenting:

• Step back and ask, Can I understand this chart in five seconds?

• Show it to someone else and ask them to explain what they see.

• Revise if they miss the intended insight.

A chart is only successful if your audience understands it quickly and accurately.

Final Thoughts

Making informative charts is about more than just aesthetics—it’s about communication. The best charts are those that strip away the noise, highlight what matters most, and help people see insights they might otherwise miss.

By starting with the right question, choosing the right chart type, and focusing on clarity, you can create visuals that bring data to life and make your analysis far more impactful.