Historical Context:

• 1965: Darrell Huff testified before U.S. Senate about misleading statistics
• Author of "How to Lie with Statistics" - best-selling statistics book ever
• Secret: Tobacco industry paid him to discredit smoking-cancer studies
• Was working on unpublished book: "How to Lie with Smoking Statistics"

Three Quick Tests to Spot Misleading Stats:

1. The Zoom Test

• Ask: How different would this number look if I zoomed in or out?
• Consider different time frames, geography, or demographics
• Would the trend hold with more context?

2. The Crop Test

• Ask: What's missing from the frame?
• What's been left out that would change your perspective?
• Look for omitted context or qualifying information

3. The Source Test

• Ask: Who took the picture?
• Check incentives of data collectors/presenters
• Be wary when same entity collects and presents data

Real Example - Shapiro Administration Claim:

• Claim: "300,000 Pennsylvanians could lose health coverage"
• Zoom Test: Used highest possible estimate
• Crop Test: Includes healthy adults who could work 20 hours/week will not to keep their benefits; includes ineligible people removed from Medicaid
• Source Test: Data from administration supporting their own argument

Final Gut Check:

• Ask: Do I want this data to be true?
• We're most easily fooled when numbers confirm our hopes
• Be especially skeptical of data that supports what you already believe

Bottom Line: You can't stop people from twisting numbers, but you can prevent them from tricking you.

Sources: U.S. Senate Commerce Committee Hearings (1965); Reinhart, Alex. "Huff and Puff" Significance (2014)

For more tips on evaluating statistical claims, refer to the accompanying one-page PDF.

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