How Charts Lie: Getting Smarter about Visual Information

by Alberto Cairo

Overview

A leading data visualization expert explores the negative—and positive—influences that charts have on our perception of truth.

We’ve all heard that a picture is worth a thousand words, but what if we don’t understand what we’re looking at? Social media has made charts, infographics, and diagrams ubiquitous—and easier to share than ever. We associate charts with science and reason; the flashy visuals are both appealing and persuasive. Pie charts, maps, bar and line graphs, and scatter plots (to name a few) can better inform us, revealing patterns and trends hidden behind the numbers we encounter in our lives. In short, good charts make us smarter—if we know how to read them.

However, they can also lead us astray. Charts lie in a variety of ways—displaying incomplete or inaccurate data, suggesting misleading patterns, and concealing uncertainty—or are frequently misunderstood, such as the confusing cone of uncertainty maps shown on TV every hurricane season. To make matters worse, many of us are ill-equipped to interpret the visuals that politicians, journalists, advertisers, and even our employers present each day, enabling bad actors to easily manipulate them to promote their own agendas.

In How Charts Lie, data visualization expert Alberto Cairo teaches us to not only spot the lies in deceptive visuals, but also to take advantage of good ones to understand complex stories. Public conversations are increasingly propelled by numbers, and to make sense of them we must be able to decode and use visual information. By examining contemporary examples ranging from election-result infographics to global GDP maps and box-office record charts, How Charts Lie demystifies an essential new literacy, one that will make us better equipped to navigate our data-driven world.

Product Details

ISBN-13:	9781324001560
Publisher:	Norton, W. W. & Company, Inc.
Publication date:	10/15/2019
Pages:	256
Product dimensions:	6.20(w) x 9.40(h) x 1.00(d)

About the Author

Alberto Cairo is the Knight Chair in Visual Journalism at the School of Communication of the University of Miami. He has consulted with companies and institutions such as Google and the Congressional Budget Office on visualizations. He lives in Miami, Florida.

Table of Contents

Prologue: A World Brimming with Charts xiii

Introduction 1

Chapter 1 How Charts Work 21

Chapter 2 Charts That Lie by Being Poorly Designed 53

Chapter 3 Charts That Lie by Displaying Dubious Data 81

Chapter 4 Charts That Lie by Displaying Insufficient Data 107

Chapter 5 Charts That Lie by Concealing or Confusing Uncertainty 135

Chapter 6 Charts That Lie by Suggesting Misleading Patterns 153

Conclusion: Don't Lie to Yourself (or to Others) with Charts 175

Afterword 195

Acknowledgments 203

Notes 205

Bibliography 215

Further Reading 219

Index 223

Editorial Reviews

★ 08/26/2019

Visual journalism professor Cairo (The Truthful Art), who has consulted for Google and the Congressional Budget Office, provides a valuable guide to reading charts with a critical and nuanced eye. With the use of such graphics throughout media only increasing, Cairo insists, persuasively, that “just looking at charts, as if they were mere illustrations,” is not enough; “we must learn to read them and interpret them correctly.” After offering a guide to different kinds of charts, Cairo presents the different ways they can mislead, including by using the wrong data or concealing uncertainty. His examples of misleading charts include one from an antiabortion group purporting to show Planned Parenthood’s cancer-screening and prevention services sharply declining while the abortions it provided sharply rose; Cairo patiently explains how the chart concealed and distorted information, such as by “using a different vertical scale for each variable.” By also criticizing staunchly liberal New York Times columnist Paul Krugman for using a chart depicting the annual U.S. murder rate that omits data from more recent years, Cairo even-handedly demonstrates that the misuse of infographics is not confined to one political side. At a time of widespread concern over disinformation in the media, Cairo provides a valuable corrective to the acceptance of numbers, and their visual representation, as having objective truth. (Oct.)

Publishers Weekly

"This book will open your eyes to how everyone uses visuals to push agendas. A master visual designer, Alberto Cairo shows you how to read charts and decode design. After this book, you can’t look at charts with a straight face!"

Kaiser Fung

2019-08-18
As this entertaining addition demonstrates, the "how to lie with statistics" genre is alive and well.

Cairo (Chair, Visual Journalism/Univ. of Miami; The Truthful Art: Data, Charts, and Maps for Communication, 2016, etc.) points out that "charts may lie…because they display either the wrong information or too little information. However, a chart can show the right type of information and lie anyway due to poor design or labeling." In a cheerful introductory chapter, the author explains that, while writing was invented about 5,000 years ago and charts weren't used until the late 1700s, both are encoded forms of communication with a structure and vocabulary. Readers receive well-researched information about the makeup of a chart along with the warning that this knowledge, like rules of grammar, is necessary but not sufficient. It's essential to pay attention. Cairo begins with a U.S. map, almost entirely red, that many claim shows the overwhelming popularity of Donald Trump in 2016. But how could that be if he received only 46 percent of the vote? The trick is that the map label shows not voters but counties with Trump majorities. Since large counties (rural) mostly voted for him and small counties (urban) didn't, such a map is overwhelmingly red. The map, although real, is used to lie. In the generously illustrated chapters that follow, the author delivers a painless, if often uncomfortable education. On a trivial level, one must know what a chart is measuring. A chart of homeless schoolchildren in Florida reveals counties with more than 20 percent. The streets are not full of sleeping students because "homeless" is not defined as "no home" but rather as "lacking a fixed, regular nighttime residence." There are plenty of no-brainers, sadly widely ignored, such as, "correlation is not causation." The graph showing that cigarette smoking increases in nations with a greater life expectancy does not prove that smoking is healthy.

An ingenious tool for detecting flaws in charts, which nowadays seem mostly deliberate.

Kirkus Reviews

"Alberto Cairo has written a wise, witty, and utterly beautiful book. You couldn’t hope for a better teacher to improve your graphical literacy."

Tim Harford

"I wish we lived in a world where you didn’t need to read Alberto Cairo’s How Charts Lie, a robust guide to self-defense against graphs and figures designed to mislead. But here we are, and yes, you do."

Jordan Ellenberg

"[Cairo’s] book could not be more timely."

Economist

"A picture may be worth a thousand words, but only if you know how to read it. In this book, Alberto Cairo teaches us how to get smarter about visual information by reading charts with attention and care. I found a lot to steal here, and you will, too."

Austin Kleon

"This book offers a succinct, elegant, accessible look at the ways data can be represented or misrepresented and is a perfect primer for anyone who cares about the difference."

Charles Wheelan

"A powerful reference that advises consumers how to better interpret the data being represented in graphic form."

Reviewer's Choice - Midwest Book Review

"Alberto Cairo shares great examples of data visualization and storytelling for anyone who wants to dig into their data."

Dona Wong

"A must-read for anyone who wants to stay informed."

Cathy O’Neil