Data-Viz Best Practices
📋 What it is
A good chart is honest and clear: start axes at zero when comparing, label everything, and don’t clutter.
🗣️ Coach says
Charts can mislead — on purpose or by accident. Cutting off the bottom of a bar axis makes tiny differences look huge. Best practice: label axes, start bars at zero, keep it simple, and let the data — not decoration — tell the story.
🧠 Memory hook
Honest chart rules: bars start at ZERO, everything is LABELED, and no 3-D clutter hiding the truth.
😂 Giggle
Why did the correlation break up with the causation?
Everyone kept confusing them for the same thing!
😲 Whoa!
News graphics have been caught starting a bar axis at 90 instead of 0, making a small change look like a giant cliff — the #1 misleading-chart trick.
✅ Quick check: Why should a bar chart’s value axis usually start at zero?
Say your answer out loud first — then reveal.
So the bar heights honestly show the real sizes of the differences.
A cut-off axis exaggerates small gaps and misleads the reader.
🪄 Trick question: A flashy 3-D pie chart with shadows — is fancier always clearer?
Careful — think it through, then reveal.
No — decoration often distorts sizes and hides the data.
Extra visual clutter (3-D, shadows) makes slices harder to compare accurately.
🧪 Try it! (2 minutes)
Find a chart in a book or online and check: does its bar axis start at zero? Is everything labeled?