Day 20: How to (Not) Lie with Statistics · Day 20: How to (Not) Lie with Statistics Daniel J....

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Day 20: How to (Not) Lie with Statistics Daniel J. Mallinson School of Public Affairs Penn State Harrisburg [email protected] PUBPL 304 Mallinson Day 20 October 06, 2017 1 / 17

Transcript of Day 20: How to (Not) Lie with Statistics · Day 20: How to (Not) Lie with Statistics Daniel J....

Page 1: Day 20: How to (Not) Lie with Statistics · Day 20: How to (Not) Lie with Statistics Daniel J. Mallinson School of Public A airs Penn State Harrisburg mallinson@psu.edu PUBPL 304

Day 20: How to (Not) Lie with Statistics

Daniel J. Mallinson

School of Public AffairsPenn State [email protected]

PUBPL 304

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Road map

Discuss how to identify a misleading use of data

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Opening Question

Have you encountered examples of misleadingpresentations of data? How did you know?

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Know Your Sample (Huff Ch. 1)

Issues Raised in Chapter 1

Sampling frame

Importance of respresentative sample

Non-response bias

Self-reported data

Unknowing “rigging”

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Famous Example - Alf Landon wins!

1936 Literary Digest Poll

Figure: “Alf Landon,” public domainFigure: “FDR” by FDR Presidential Library,

CC BY 2.0

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Famous Example1936 Literary Digest Poll

Figure: “1936 Electoral College” by AndyHogan14, public domain

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Misleading Comparisons

BP Oil Spill

“The Gulf of Mexico is a very big ocean. The amount of volume ofoil and dispersant we are putting into it is tiny in relation to the totalwater volume.” (Tony Hayward, BP CEO)

Ground Water Removal by Bottled Water Companies

http://www.lulu.com/items/volume_62/957000/957317/9/

print/957317.pdf

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Misleading Figures (Duff Ch. 5)

How to spot a misleading graph

https:

//www.youtube.com/watch?v=E91bGT9BjYk&feature=youtu.be

Labels

Numbers

Scale

Context

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Misleading FiguresWatch Those Axes!

Figure: Blitz, Shelby 2017Mallinson Day 20 October 06, 2017 9 / 17

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Misleading FiguresWatch Those Axes!

Figure: Bump, Philip 2015

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Misleading FiguresWatch Those Axes!

Figure: Bump, Philip 2015

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Misleading FiguresWatch Those Axes!

Figure: Bump, Philip 2015

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Misleading FiguresWatch Those Axes!

Figure: Bump, Philip 2015

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Misleading Figures

Correlation vs. Causation

Figure: “Spurious Correlations” by Tyler Viglen licensed under CC BY 4.0

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Bad InfographicsWhat is the problem here?

Figure: Knopfler, Jack 2015

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Bad InfographicsWhat is the problem here?

Figure: Knopfler, Jack 2015

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Homework

Complete the provided homework sheet. Due Monday

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