🛠️ House style for charts

💡 Use Case

• One page of rules for any chart I make: for work, for the course, for 📂 Slack in the System - 2025 issues.
• Written on Sunday 16 February during flashcards on base rates, four days after a meeting in which a bar chart with a cut axis nearly argued the other side's case for them.
• It is 🧭 Five questions to ask a chart turned round: if I would ask it of someone else's chart, mine answers it before anyone has to.

How I use it

1. Grey first. Every line, bar and label in grey.
2. One colour, on the single mark the sentence is about.
3. Axis from zero, unless stated, and then stated on the chart in words.
4. The interval is always drawn. A point without its range is an opinion.
5. The title is the claim, as a sentence. The axis labels say the units.
6. Label the lines directly. No legend to look back and forth at.
7. Say what is missing: which rows were dropped, which weeks, how many.
8. Monthly points stay points. No smoothing a step into a trend.

⚖️ Pros & Cons

Pros

• Grey by default, one colour for the point. If I cannot say which mark gets the colour, I do not yet know what the chart is for.
• Drawing the interval every time has changed what I am willing to claim. The triage result in May was a range on a slide because the rule left no room for a single bar.
• Bao Nguyen approves, which is not nothing.

Cons

• An axis from zero flattens small real changes. The rule allows an exception; the exception has to be printed on the chart.
• Grey charts look unfinished to people who like dashboards. Twice I have been asked whether the colours failed to load.
• It is a style, not a method. A tidy chart of the wrong comparison is still wrong.

🔄 Alternatives

• The spreadsheet's defaults: six colours, a legend, a shadow.
• Huff's whole book as a checklist of what not to do: 📕 How to Lie with Statistics. Funnier than my page, and longer.