2. Statistical Deception . Lying with statistics 
Statistical Deception  Lying with statistics  Putting a “positive spin” on the facts

3. Statistical deception is not. necessarily a bad thing,
Statistical deception is not necessarily a bad thing, but you need to be aware of it rather than just accepting statistics at face value.

4. Many problems with statistics involve problems with gathering the data:

5. 1. Non-representative. samples . too small . too large 
1. Non-representative samples  too small  too large  not randomly chosen * convenience sample * purposely chosen wrong

9. 2. Generalizing to the. wrong population . sample is drawn from a
2. Generalizing to the wrong population  sample is drawn from a different population than the results imply

12. 3. Comparing apples and. oranges . groups being compares
3. Comparing apples and oranges  groups being compares were different to begin with  difference is due to something other than the results imply

13. 4. Survey bias  leading questions

14.  “Good boy” Effect People will give the answer they think you want to hear.

15.  “NOYB” effect

16. The more personal a question is (the more it is “none of your business”), the more likely people are to lie.

17. 5. Placebo effect . In medicine a placebo is a
5. Placebo effect  In medicine a placebo is a fake treatment actually helps because people think it will work.

18. . Doesn’t have to deal with. medicine. . In general, when people
 Doesn’t have to deal with medicine.  In general, when people think they are being watched or treated, they often act differently than they would otherwise.

20. Other issues can come up in interpreting and publicizing statistical results:

21. 1. Convenient averages •. Choosing the average that
1. Convenient averages • Choosing the average that makes you look the best (or your opponent look the worst), even if it’s not really a “typical” average • Ask …Is the number they give really “average”?

22. 2. Assuming everybody is. average (or close to it) •
2. Assuming everybody is average (or close to it) • …How spread out are things?

23. 3. Not adjusting for different. sample sizes •. Comparing raw numbers
3. Not adjusting for different sample sizes • Comparing raw numbers instead of percentages

26. Which is true. . Raw crimes are going up,. mostly because the
Which is true?????  Raw crimes are going up, mostly because the country’s population is increasing.  Your risk of being a crime victim has never been lower.

27. 4. Not adjusting money amounts for inflation

31. 5. Screwing up the math

32. • Classic example: Is spinach a high-iron food?

33. No—in the initial report a decimal point was misplaced. •
No—in the initial report a decimal point was misplaced. • Spinach was reported to have 1000 times as much iron as it actually does. • In fact, spinach is pretty much equivalent to any other leafy green vegetable.

34. 6. Extrapolating from a. partial result. . Does a low-salt diet lower
6. Extrapolating from a partial result.  Does a low-salt diet lower blood pressure?

35. Sometimes—but mostly not. •. In otherwise healthy. people, there is no
Sometimes—but mostly not. • In otherwise healthy people, there is no correlation at all between salt consumption and blood pressure.

36. • In patients with serious hypertension, reduced salt has been shown to be one of many treatments that may lower blood pressure.

37. • It doesn’t always work,
though—and some patients
BP actually increases with
less salt consumption.
• About seventy years of
research have been at best
inconclusive.

38. 7. Assuming cause and effect

41. •. Remember: correlation. just means “relationship” •
• Remember: correlation just means “relationship” • A confounding variable may be skewing the results.

42. 8. Ignoring Occam’s Razor •. complex or unbelievable. explanations •
8. Ignoring Occam’s Razor • complex or unbelievable explanations • Occam’s Razor says the simplest explanation is generally the best.

43. • Always consider the simplest explanation first.

45. Was there a conspiracy to cover up the fact that President Obama was not born in the United States?

46. •. Some people have. claimed that the President
• Some people have claimed that the President Obama’s birth certificate is fake.

47. • Many independent experts have examined the birth certificate. They determined the certificate was authentic, had a raised seal, and was of the same format as others issued in Hawaii at the time it was requested.

48. •. Linda Lingle, a Republican. who was the governor of
• Linda Lingle, a Republican who was the governor of Hawaii when Obama ran for office, verified that the birth certificate was genuine.

49. •. In addition, it has been. noted that birth. announcements were
• In addition, it has been noted that birth announcements were published in the Honolulu papers the day after Obama’s birth:

50. •. A nurse who worked with. the doctor who attended
• A nurse who worked with the doctor who attended the birth remembers the doctor commenting on the birth, because having a black father was very unusual in Hawaii at the time.

51. •. Real estate and tax. records show Stanley. Ann Dunham Obama and
• Real estate and tax records show Stanley Ann Dunham Obama and Barack Obama, Sr. lived in Honolulu at the time Barack Obama, Jr. was born.

52. •. Though some critics still. claim the President is not
• Though some critics still claim the President is not a “native-born” American citizen, this claim doesn’t pass Occam’s Razor— which is the reason courts have refused to consider them.

53. 9. Changing the subject . a. k. a. “Moving the bullseye
9. Changing the subject  a.k.a. “Moving the bullseye to fit the arrows”  saying a result means something different than it really does  putting a “good spin” on the data

54. . finding one small thing. about the results that
 finding one small thing about the results that supports what you want to find

55. Suppose you were the police chief in a town with a crime problem …

59. 1993 – 94 … 100 more 1994 – 95 … 75 more 1995 – 96 … 50 more 1996 – 97 … 25 more

61. 10. Reporting information. from biased sources. that have a vested
10. Reporting information from biased sources that have a vested interest.

64. Always ask “Who says so”?
Try to get information from neutral parties who don’t have a stake in the outcome.

65. 11. Using a non-standard. significance level 
11. Using a non-standard significance level  deciding after the fact on a level that guarantees significance

66. 12. Misuse of the word. “significant” . implying significant means
12. Misuse of the word “significant”  implying significant means big, important, or dramatic  REMEMBER: it just means “unlikely to have happened by chance”

67. 13. Discounting significance because something is “just statistics”