Stupid Statistics in the News

  • Thread starter Quaoar
  • Start date
  • #1
182
0

Main Question or Discussion Point

Just read http://www.alertnet.org/thenews/newsdesk/N19303337.htm", which conveys the message that the war in Iraq is going so badly, that the suicide rate has doubled. However, this is simply a Poisson distribution, and the values they list do not seem to indicate that the mean value has increased at all in the past 3 years.

I was just wondering if anyone else has seem some particularly stupid statistics in a news story that they'd like to share.
 
Last edited by a moderator:

Answers and Replies

  • #5
BobG
Science Advisor
Homework Helper
185
80
People always have trouble interpreting statistics.

If there were a fatal disease that would strike 1 out a 1000 people, and a person decided to get tested for the disease and the test were 99% accurate, and the person tested positive, most people would be pretty certain they were going to die.

Then again, if you asked people what the average human body temperature was, just about all Americans would get it wrong, while most Europeans would be correct.
 
  • #6
berkeman
Mentor
57,693
7,721
People always have trouble interpreting statistics.

If there were a fatal disease that would strike 1 out a 1000 people, and a person decided to get tested for the disease and the test were 99% accurate, and the person tested positive, most people would be pretty certain they were going to die.

Then again, if you asked people what the average human body temperature was, just about all Americans would get it wrong, while most Europeans would be correct.
Is that because most Europeans use, well, THAT kind of body thermometer? I've heard it's much more accurate, but I've been a bit reluctant to use it myself. :rolleyes:
 
  • #7
D H
Staff Emeritus
Science Advisor
Insights Author
15,393
683
Its because Europeans use the metric system. 37C is easier to remember than 98.6F.
 
  • #8
Hurkyl
Staff Emeritus
Science Advisor
Gold Member
14,916
19
As I recall, the 98.6° myth is exactly what BobG was mentioning.
 
  • #9
BobG
Science Advisor
Homework Helper
185
80
Its because Europeans use the metric system. 37C is easier to remember than 98.6F.
37 C is 36.8 C rounded to two significant digits.

98.6 F is 37 C converted to Fahrenheit. When you convert a number with only two significant digits to a three digit number, you run into a false sense of accuracy.

(Technically, Europeans wouldn't be more accurate; they'd be more correct.)
 
  • #10
Moonbear
Staff Emeritus
Science Advisor
Gold Member
11,490
52
37 C is 36.8 C rounded to two significant digits.

98.6 F is 37 C converted to Fahrenheit. When you convert a number with only two significant digits to a three digit number, you run into a false sense of accuracy.

(Technically, Europeans wouldn't be more accurate; they'd be more correct.)
Actually, the problem isn't unit conversion, but old data vs newer data. 37.0 C or 98.6 F was the average body temperature of healthy subject in the first study looking at human body temperature under a range of conditions. That study used a foot long thermometer in the axillary region (under the armpit). http://qjmed.oxfordjournals.org/cgi/content/full/95/4/251

A more recent study, using digital thermometers to measure oral temperature reports a lower average.
A critical appraisal of 98.6 degrees F, the upper limit of the normal body temperature, and other legacies of Carl Reinhold August Wunderlich

P. A. Mackowiak, S. S. Wasserman and M. M. Levine
Medical Service, Veterans Affairs Medical Center, Baltimore, MD 21218.

OBJECTIVE--To evaluate critically Carl Wunderlich's axioms on clinical thermometry. DESIGN--Descriptive analysis of baseline oral temperature data from volunteers participating in Shigella vaccine trials conducted at the University of Maryland Center for Vaccine Development, Baltimore. SETTING--Inpatient clinical research unit. PARTICIPANTS--One hundred forty-eight healthy men and women aged 18 through 40 years. MAIN MEASUREMENTS--Oral temperatures were measured one to four times daily for 3 consecutive days using an electronic digital thermometer. RESULTS--Our findings conflicted with Wunderlich's in that 36.8 degrees C (98.2 degrees F) rather than 37.0 degrees C (98.6 degrees F) was the mean oral temperature of our subjects; 37.7 degrees C (99.9 degrees F) rather than 38.0 degrees C (100.4 degrees F) was the upper limit of the normal temperature range; maximum temperatures, like mean temperatures, varied with time of day; and men and women exhibited comparable thermal variability. Our data corroborated Wunderlich's in that mean temperature varied diurnally, with a 6 AM nadir, a 4 to 6 PM zenith, and a mean amplitude of variability of 0.5 degrees C (0.9 degrees F); women had slightly higher normal temperatures than men; and there was a trend toward higher temperatures among black than among white subjects. CONCLUSIONS--Thirty-seven degrees centigrade (98.6 degrees F) should be abandoned as a concept relevant to clinical thermometry; 37.2 degrees C (98.9 degrees F) in the early morning and 37.7 degrees C (99.9 degrees F) overall should be regarded as the upper limit of the normal oral temperature range in healthy adults aged 40 years or younger, and several of Wunderlich's other cherished dictums should be revised.
P. A. Mackowiak; S. S. Wasserman; M. M. Levine
A critical appraisal of 98.6 degrees F, the upper limit of the normal body temperature, and other legacies of Carl Reinhold August Wunderlich
JAMA, Sep 1992; 268: 1578 - 1580.
http://jama.ama-assn.org/cgi/conten...INDEX=0&sortspec=relevance&resourcetype=HWCIT

And, upon a little further digging, I found this:
When Mackowiak tested an alleged Wunderlich thermometer, borrowed from a medical museum, he found that it was calibrated too high--which might explain the German doctor's higher numbers.
http://findarticles.com/p/articles/mi_m1511/is_n1_v14/ai_13652010

Though, in reality, the worst misinterpretation is that people don't recognize the 37 C or 98.6 F measure is average body temperature, not normal body temperature. Normal body temperature is subject to individual variation.
 
  • #11
Ivan Seeking
Staff Emeritus
Science Advisor
Gold Member
7,213
176
"Ten percent of drivers choose to talk on their cell phones while having accidents" - SNL
 

Related Threads on Stupid Statistics in the News

  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
17
Views
2K
  • Last Post
Replies
8
Views
2K
  • Last Post
2
Replies
33
Views
6K
  • Last Post
2
Replies
37
Views
4K
  • Last Post
Replies
5
Views
1K
Replies
13
Views
2K
  • Last Post
Replies
2
Views
2K
Replies
6
Views
2K
Top