The One Rule That Will Change Every Chart You Make
- 12 minutes ago
- 3 min read
Introduction: The Most Boring Topic at Any Conference
Data visualisation. Charts, tables, numbers. Piotr Garlej opens his session by admitting it freely: there is no more boring topic at a conference. We have all sat through slides packed with colour-coded bar charts and thought about excusing ourselves. The point of this talk is to make sure your audience never thinks that about yours.
The Problem With Most Data Visualisation Rules
The internet is full of rules for presenting data. Do not use more than three lines in a line chart. Keep it simple. Avoid pie charts. The trouble is that almost every rule falls apart the moment you find a good exception. Ask an expert whether a rule holds and they will almost always say: it depends. Which, as Piotr puts it, is a conversation killer.
So rather than adding to the pile of half-true guidelines, he went looking for something more fundamental.
The Google Rule
The ultimate rule comes from an unlikely source: Google's original design philosophy. Unlike every other website, Google did not want users to spend time on their page. If you were still searching after several attempts, Google had failed. Their aim was to get you to what you needed as quickly as possible.
The principle for data visualisation is exactly the same: design your charts so clearly, so simply, and so obviously that your audience spends as little time as possible analysing and understanding them. Everything else follows from this.
4 Guidelines to Put Into Practice
Avoid legends — wherever possible, integrate labels directly into the chart. Forcing the audience to look left and right between a legend and the data wastes time and attention. Remove the friction.
Remove information noise — anything on a slide that does not contribute to the core message is a distraction. Vertical axes with numbers already shown above each column, unnecessary gridlines, rotated category labels — strip them out. Tidier slides are faster to read.
Focus on one item — the infamous Afghanistan war slide, shown to General Stanley McChrystal, is the cautionary tale here. His response: "If we understand this slide, we will win this war." They did not. Divide your content into foreground and background. Highlight the one thing that matters. Change the colour of a single column. That is often all it takes.
Avoid cliché — default chart styles, standard templates, and tired visual formats signal that no thought has gone into the presentation. When every other website in the early internet era looked the same, Google looked completely different. The same opportunity exists every time you open a slide deck.
A Word on Pie Charts
Many experts have declared pie charts dead. Piotr disagrees — with a caveat. If the goal is to show differences between values, use a column, bar, or slope chart. If the goal is to show trends, use a line or area chart. But if the goal is to show structure — the composition of a whole — a pie or donut chart remains a perfectly valid choice. The rule is not never use them. The rule is use the right chart for the job.
Final Thoughts: Real Expertise Is Specific
Piotr closes with a challenge to the reflex of saying "it depends" when faced with a difficult question. Real experts do not hide behind vagueness — they pause, reflect, and say: it depends on X, Y, and Z. That specificity is what makes advice useful. Apply the same standard to your data visualisations. Do not just simplify — simplify with purpose, and always ask: how quickly can my audience understand this?
Join the Conversation
What is the most overcomplicated chart you have ever had to sit through — and what would you have done differently? Share your thoughts in the comments below.
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