Avoiding Data Pitfalls: How to Steer Clear of Common Blunders When Working with Data and Presenting Analysis and Visualizations

Avoid data blunders and create truly useful visualizations Avoiding Data Pitfalls is a reputation-saving handbook for those who work with data, designed to help you avoid the all-too-common blunders that occur in data analysis, visualization, and presentation. Plenty of data tools exist, along with plenty of books that tell you how to use them—but unless you truly understand how to work with data, each of these tools can ultimately mislead and cause costly mistakes. This book walks you step by step through the full data visualization process, from calculation and analysis through accurate, useful presentation. Common blunders are explored in depth to show you how they arise, how they have become so common, and how you can avoid them from the outset. Then and only then can you take advantage of the wealth of tools that are out there—in the hands of someone who knows what they're doing, the right tools can cut down on the time, labor, and myriad decisions that go into each and every data presentation. Workers in almost every industry are now commonly expected to effectively analyze and present data, even with little or no formal training. There are many pitfalls—some might say chasms—in the process, and no one wants to be the source of a data error that costs money or even lives. This book provides a full walk-through of the process to help you ensure a truly useful result. Delve into the "data-reality gap" that grows with our dependence on data Learn how the right tools can streamline the visualization process Avoid common mistakes in data analysis, visualization, and presentation Create and present clear, accurate, effective data visualizations To err is human, but in today's data-driven world, the stakes can be high and the mistakes costly. Don't rely on "catching" mistakes, avoid them from the outset with the expert instruction in Avoiding Data Pitfalls.

Table of Contents:
Preface ix Chapter 1 The Seven Types of Data Pitfalls 1 Seven Types of Data Pitfalls 3 Pitfall 1: Epistemic Errors: How We Think About Data 3 Pitfall 2: Technical Traps: How We Process Data 4 Pitfall 3: Mathematical Miscues: How We Calculate Data 4 Pitfall 4: Statistical Slipups: How We Compare Data 5 Pitfall 5: Analytical Aberrations: How We Analyze Data 5 Pitfall 6: Graphical Gaffes: How We Visualize Data 6 Pitfall 7: Design Dangers: How We Dress up Data 6 Avoiding the Seven Pitfalls 7 “I’ve Fallen and I Can’t Get Up” 8 Chapter 2 Pitfall 1: Epistemic Errors 11 How We Think About Data 11 Pitfall 1A: The Data-Reality Gap 12 Pitfall 1B: All Too Human Data 24 Pitfall 1C: Inconsistent Ratings 32 Pitfall 1D: The Black Swan Pitfall 39 Pitfall 1E: Falsifiability and the God Pitfall 43 Avoiding the Swan Pitfall and the God Pitfall 44 Chapter 3 Pitfall 2: Technical Trespasses 47 How We Process Data 47 Pitfall 2A: The Dirty Data Pitfall 48 Pitfall 2B: Bad Blends and Joins 67 Chapter 4 Pitfall 3: Mathematical Miscues 74 How We Calculate Data 74 Pitfall 3A: Aggravating Aggregations 75 Pitfall 3B: Missing Values 83 Pitfall 3C: Tripping on Totals 88 Pitfall 3D: Preposterous Percents 93 Pitfall 3E: Unmatching Units 102 Chapter 5 Pitfall 4: Statistical Slipups 107 How We Compare Data 107 Pitfall 4A: Descriptive Debacles 109 Pitfall 4B: Inferential Infernos 131 Pitfall 4C: Slippery Sampling 136 Pitfall 4D: Insensitivity to Sample Size 142 Chapter 6 Pitfall 5: Analytical Aberrations 148 How We Analyze Data 148 Pitfall 5A: The Intuition/Analysis False Dichotomy 149 Pitfall 5B: Exuberant Extrapolations 157 Pitfall 5C: Ill-Advised Interpolations 163 Pitfall 5D: Funky Forecasts 166 Pitfall 5E: Moronic Measures 168 Chapter 7 Pitfall 6: Graphical Gaffes 173 How We Visualize Data 173 Pitfall 6A: Challenging Charts 175 Pitfall 6B: Data Dogmatism 202 Pitfall 6C: The Optimize/Satisfice False Dichotomy 207 Chapter 8 Pitfall 7: Design Dangers 212 How We Dress up Data 212 Pitfall 7A: Confusing Colors 214 Pitfall 7B: Omitted Opportunities 222 Pitfall 7C: Usability Uh-Ohs 227 Chapter 9 Conclusion 237 Avoiding Data Pitfalls Checklist 241 The Pitfall of the Unheard Voice 243 Index 247