📐 Concept Map 3: Design Principles
STAT 80B - Data Visualization | Due Week 9
Overview
This week’s concept map asks you to synthesize the visualization design principles covered in Wilke Chapters 17–26 into a single, organized visual map. Rather than summarizing each chapter separately, you’ll build a connected network of ideas showing how the principles relate to each other.
Format: Hand-drawn or digital, 1–2 pages (a single dense page is fine)
Due: Beginning of class, Week 9
What to Include
Your concept map should cover the following core ideas. You don’t need to use every bullet — focus on making meaningful connections between the ones you include.
Core Principles
- Proportional ink — shaded areas must scale with data values; bars must start at zero
- Avoiding 3D — 3D distorts perception without adding information
- Redundant coding — encoding the same variable through multiple aesthetics (color + shape, etc.)
- Accessibility — colorblind-friendly palettes, sufficient contrast, legible text
Color
- When to use sequential, diverging, and qualitative palettes
- Avoiding rainbow/jet colormaps
- Using color to highlight, not just to distinguish
Multi-Panel Design
- Small multiples / facets
- Compound figures (panels A, B, C)
- When to combine vs. separate plots
Common Pitfalls to Avoid
- Truncated axes (the misleading y-axis)
- 3D charts that distort perspective
- Overplotting (and how to handle it)
- Chartjunk and unnecessary decoration
Good vs. Bad Design
Include at least one example of a good design choice and one example of a bad design choice — drawn or described simply. They don’t need to be detailed; a labeled sketch is enough.
Suggested Steps
- Skim Wilke Ch 17–26 — you don’t need to read every chapter in detail; use the headings, figures, and captions to get the key ideas.
- List the concepts — write all the principles and terms you want to include (aim for 15–25 concepts).
- Group them — find natural clusters (e.g., “ink & area,” “color choices,” “layout & panels”).
- Draw the map — start with your groups as nodes, then add connecting lines with short labels describing the relationship (e.g., “violates”, “is a case of”, “corrected by”, “requires”).
- Add examples — annotate 2–3 nodes with a brief real-world example or sketch.
- Review — make sure someone unfamiliar with the material could follow the logic of your map.
Example Connection Labels
Use short, meaningful phrases on your connecting arrows or lines:
- “violates proportional ink”
- “is corrected by”
- “requires”
- “is a type of”
- “works best when”
- “fails for colorblind readers unless”
- “can cause”
Grading
Your concept map will be evaluated on:
| Criterion | Description |
|---|---|
| Coverage | Key principles from Ch 17–26 are represented |
| Connections | Relationships between concepts are clearly labeled |
| Pitfalls | At least 3 common pitfalls are included and contextualized |
| Examples | At least 1 good and 1 bad design example is included |
| Clarity | The map is readable and logically organized |
There is no single correct answer — different students will emphasize different connections. What matters is that your map reflects genuine engagement with the material and shows how the ideas fit together.
Submission
Scan or photograph your concept map (or export the digital version) and upload it to Canvas before the start of Week 9 class.
- Avoid making a simple list in disguise — the connections between nodes are what make it a map
- It’s okay (and good!) if your map has cycles or bidirectional arrows
- If a concept connects to many others, put it at the center
- Handwritten is perfectly fine — neatness matters less than clarity of thinking
Resources
- Wilke’s book (free online): https://clauswilke.com/dataviz/
- Ch 17: Proportional Ink
- Ch 18: Handling Overlapping Points
- Ch 19: Common Pitfalls of Color Use
- Ch 20: Redundant Coding
- Ch 21: Multi-Panel Figures
- Ch 22: Titles, Captions, and Tables
- Ch 26: Don’t Go 3D
- Thursday’s lecture slides (slides2.html) include a summary of the main ideas