The Mortal Sins Of Chart Design

For almost 30 years, Yale professor Edward Tufte has waged a crusade against poor chart design.

As a result, he’s radically changed the way people think about visualising data.

Yet some of his simplest, least disputable lessons are widely unheeded today.

Let’s look at three of these simple rules and the people guilty of breaking them.

We begin with iTunes and why its design is inexcusable.

Take a look for yourself >>
photo courtesy of Jonny Goldstein

Zebra-Striped Rows Are No Good

iTunes is a great program -- hence its millions of users.

But looking up information about your songs is much harder than it has to be, thanks to these zebra stripes. Alternating background colours is probably never a good idea, but if you're going to do it, the stripes should be three rows wide, not one. Your eye can distinguish between the top, middle, and bottom element of a group effortlessly, and fewer stripes are less of a distraction, as you can see on the next slide.

3 Rows Are Much Better Than 1

Column 1 Column 2 Column 3 Row 1 4 2 76 Row 2 6 6 3 Row 3 15 12 8 Row 4 22 87 76 Row 5 34 90 123 Row 6 90 232 12 Row 7 78 89 45 Row 8 78 78 67 Row 9 45 123 566 Row 10 8 3 219 Row 11 21 24 32

Row 1
Row 2 Column 1
4
6 Column 2
2
6 Column 3
76
3 Row 3
Row 4
Row 5 15
22
34 12
87
90 8
76
123 Row 6
Row 7
Row 8 90
78
78 232
89
78 12
45
67 Row 9
Row 10
Row 11 45
8
21 123
3
24 566
219
32

The Right Way To Make A Table

Row 1
Row 2 Column 1
4
6 Column 2
2
6 Column 3
76
3 Row 3
Row 4
Row 5 15
22
34 12
87
90 8
76
123 Row 6
Row 7
Row 8 90
78
78 232
89
78 12
45
67 Row 9
Row 10
Row 11 45
8
21 123
3
24 566
219
32Zebra stripes that alternate every row are definitely ugly, and probably useless.

Making the stripes three rows wide is a massive improvement, but as you can see, a plain grid does just as well, and is easier on the eye. Always aim to get rid of any ink that isn't data and isn't essential to making your chart clear.

Pie Charts Are A Waste Of Space

Like Apple, Google generally uses clear, minimal designs.

The use of pie charts as the default mode of presenting data in Google Analytics, however, is a complete disaster. Tech blogger Coda Hale points out: 'This piechart uses 78,050 pixels to display a single fact -- that 9.94% of all visitors had previously visited the site -- resulting in a spectacular data-point-to-pixel ratio of 0.0013%.'

Lines Are Clear, Pies Are Obscure

Pie charts are almost always a mistake.

When there isn't much data, they are a waste of space. Once you have more than a few data points, however, the eye can only distinguish massive differences. Judging the relative areas of pie-shaped regions simply isn't something we're very good at.

Heavy Gridlines Are Distracting

Google and Apple aren't perfect, but for really bad chart design you can always count on the federal government.

This is a summary of stimulus spending from the Government Accountability Office. Knowing where one column or row ends and another begins is important, of course, but lots of heavy lines create confusion and emphasise the grid, rather than the data we actually care about.

The Less Noise, The Better

There is never a good reason to include thick, dark lines in your charts.

Soft, dotted lines. As with the zebra stripes, marking off every row is a waste - we can track clusters of three rows perfectly well. Simply by removing some lines and making the remaining ones softer, we can make the GAO's chart massively more readable.

Learn More About Good Chart Design

Making any of these mistakes -- using heavy grids or zebra stripes in tables, or displaying information in pie charts -- will ensure your charts are harder to follow than they have to be.

But avoiding them isn't enough to make your presentations look good. Take a look at Tufte's work for yourself to learn much more about how to display information effectively.

NOW WATCH: Ideas videos

Business Insider Emails & Alerts

Site highlights each day to your inbox.

Follow Business Insider Australia on Facebook, Twitter, LinkedIn, and Instagram.