dale peet - golden rules of data visualisation

Golden Rules of Data Visualisation

About me

Dale PeetSenior Business Intelligence Analyst @ Cranewarehttps://uk.linkedin.com/in/dale-peet

What is the purpose of a chart?

?

What is the purpose of a chart?

To turn Data into Knowledge

What is the purpose of a chart?

Quickly!

Rule #1Avoid things our

eyes aren’t good at

What are our eyes bad at?

▪Areas▪Angles▪Lengths

Think you’re good at judging area?

Think you’re good at judging area?

So why would we be good with tree charts

Or area charts

Particularly area charts

We’re bad at judging lengths

We’re bad at judging lengths

Don’t use this chart!

3D is misleading

3D is misleading

3D is awful

3D is awful

Yellow: 4Red: 4Blue: 3

In fact Pie Charts are just terrible!

Which segment is biggest?Which is the second biggest?

The only useful Pie Chart!

So what are our eyes good at?

▪Relative Height▪Trend of a line– Is it going up or down.

So is this a good chart?

No!

Bike

s

Hel

met

s

Lock

s

Bike

s

Hel

met

s

Lock

s

Bike

s

Hel

met

s

Lock

s

Bike

s

Hel

met

s

Lock

s

Sum of Jan Sum of Feb Sum of March

Sum of April

0

20

40

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140

Yellow BikesSturdy LocksSmall HelmetsRed BikesMedium HelmetsLarge HelmetsBlue BikesBlack BikesBasic Locks

Rule #2Less is More

Less is more

1 second example

Jan Feb March April0

10

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60

Red Bikes Blue Bikes Yellow Bikes Black Bikes

?

Jan Feb March April0

10

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60

Red Bikes Blue Bikes Yellow Bikes Black Bikes

Sum of Jan Sum of Feb Sum of March Sum of April0

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Bike Sales

Sum of Jan Sum of Feb Sum of March Sum of April0

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National Bike Sales per month for all

colours

Rule #3Always start at

the beginning

Sum of Jan Sum of Feb Sum of March Sum of AprilBikes

100

105

110

115

120

125

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Bike Sales

Sum of Jan Sum of Feb Sum of March Sum of April0

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Bike Sales

So should we do this?

Jan Feb Mar Apr May0%

20%

40%

60%

80%

100%

Quota Attainment

Think of a better way to show the data!

Jan Feb Mar Apr May

-4%

-3%

-2%

-1%

0%

1%

2%

3%

4%

Variance from Quota

Rule #4Don’t go mad with

colour

Looks pretty right?

Sum of Jan Sum of Feb Sum of March Sum of April0

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Yellow BikesRed BikesGreen BikesBlue Bikes

Not so pretty now…

Sum of Jan Sum of Feb Sum of March Sum of April0

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Yellow BikesRed BikesGreen BikesBlue Bikes

8% of men are colour blind

Everyone loves traffic lights!

So how should we

use colour?

Much better

Sum of Jan Sum of Feb Sum of March Sum of April0

20

40

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Yellow BikesRed BikesBlue BikesBlack Bikes

Use colour as a highlight

Jan Feb Mar Apr May0

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Rule #5Think about

what decision the chart will

enable

?

Summary

▪ Avoid things our eyes aren’t good at▪ Less is more▪ Start at the beginning▪ Don’t go mad with colour▪ Think about what decisions the chart will enable