| name | Data Visualization |
| description | Select the right chart type by story intent, apply colorblind-safe palettes, annotate insights, and remove clutter for clear data communication. |
Purpose
Turn data into visuals that communicate. A good chart answers one question clearly. A bad chart confuses many questions at once. This skill covers chart selection, color theory, annotation, and the principle that the chart title should BE the insight.
Steps
- Start with the question: what does the audience need to understand?
- Select the chart type based on the relationship in the data
- Apply the colorblind-safe palette
- Write the title as the insight, not the metric name
- Annotate the key data point
- Remove all clutter: gridlines, borders, unnecessary legends, 3D effects
- Add source attribution
Chart Selection by Story Intent
| Intent | Best Chart Type | Example |
|---|
| Compare categories | Horizontal bar | "Sales by region" |
| Show trend over time | Line | "Monthly revenue, 2023-2024" |
| Part of whole | Stacked bar or pie (max 5) | "Revenue split by product line" |
| Correlation | Scatter | "Marketing spend vs. revenue" |
| Distribution | Histogram or box plot | "Customer age distribution" |
| Ranking | Sorted horizontal bar | "Top 10 customers by revenue" |
| Composition over time | Stacked area | "Channel mix evolution" |
| Flow or conversion | Funnel or Sankey | "Sales pipeline stages" |
| Geographic | Choropleth map | "Revenue by country" |
Colorblind-Safe Palette (Mandatory)
Use the Tableau 10 palette for all data series:
| Order | Color | Hex Code |
|---|
| 1 | Blue | #4e79a7 |
| 2 | Orange | #f28e2b |
| 3 | Red | #e15759 |
| 4 | Teal | #76b7b2 |
| 5 | Green | #59a14f |
| 6 | Yellow | #edc948 |
| 7 | Purple | #b07aa1 |
| 8 | Pink | #ff9da7 |
| 9 | Brown | #9c755f |
| 10 | Gray | #bab0ac |
Never use arbitrary colors. Never rely on red/green distinction alone.
Title = Insight Principle
| Bad Title (Topic) | Good Title (Insight) |
|---|
| "Q3 Revenue" | "Q3 Revenue Grew 18% Driven by Enterprise Segment" |
| "Customer Satisfaction" | "Satisfaction Dropped Below Target for First Time in 2024" |
| "Headcount by Department" | "Engineering Grew 40% While Sales Stayed Flat" |
Annotation Rules
- Highlight the single most important data point with a contrasting color
- Add a callout or label to that point
- Gray out non-essential data series
- Use direct labels instead of legends when there are 3 or fewer series
- Place the source in small text at the bottom left
Clutter Removal Checklist
Output Format
- Chart specification: type, data mapping, colors, title (as insight)
- Annotation guide: which data point to highlight and why
- Source attribution text
Guidelines
- One chart, one message. If a chart tells two stories, make two charts.
- The audience should understand the point in under 5 seconds
- Start bar chart axes at 0 to avoid exaggerating differences
- Pie charts: maximum 5 slices. If more, use a horizontal bar chart.
- Time always flows left to right on the x-axis
- If the chart needs a paragraph of explanation, the chart has failed
