Choosing the right chart for the question

Start with the decision your reader needs to make.

A chart should answer a useful question. Decide whether the reader needs to compare values, see change, understand distribution, find a relationship, examine composition, or explore location.

Clear visual choices begin with a clear sentence about what matters.

Inspect the shape of the data.

Check field types, missing values, dates, categories, ranges, and units before choosing a visual. The cleanest format is usually the one that preserves the structure without asking the reader to decode it.

• Use meaningful column names and units.
• Keep one observation per row.
• Separate category, time, value, and annotation fields.

Choose the simplest format that carries the meaning.

Default to familiar visual forms when they answer the question well. Add novelty only when interaction, motion, or spatial structure makes the insight easier to understand.

Review the story at phone size.

Verify labels, contrast, source notes, keyboard behavior, reduced-motion alternatives, and the takeaway without relying on color alone.