Chance News 66
Quotations
"It ain’t what you don’t know that gets you into trouble. It’s what you know for sure that just ain’t so."
--Mark Twain
Quoted by Richard H. Thaler in The overconfidence problem in forecasting, New York Times, 21 August 2010.
Submitted by Paul Alper
Forsooth
The following Forsooth is from the August 23, 2010 RRS News.
An editorial was published in the Journal
of the National Cancer institute (Volume
101, issue 23, 2 December 2009) It
announced some online recourses for
journalists, including a statistics glossary,
which gave the following definitions.
P value
probability that an observed effect size is
due to chance alone
If p > 0.05, we say ’due to chance’,’not
statistically signifcant’
if p < 05, we say ‘not due to chance’,
’statistically signifcant’
Confidence interval (95% CI)
Because the observed value is only an
estimate of the truth, we know it has a
’margin of error’
The range of plausible values around the
Observed value that will contain the truth
95% at the time
jnci (vol. 102, issue 11, 2 June 2010)
subsequently published a letter
commenting on the editorial and the
statistics glossary. The authors of the
original editorial replied as follows.
Dr Lash correctly points out that the
descriptions of p values and 95%
confidence intervals do not meet the
formal frequents statistical definitions.
[…] We were not convinced that working
journalists would find these definitions
user-friendly, so we sacrificed precision for
utility.
Submited by Laurie Snell
Risk reduction
Burger and a statin to go? Or hold that, please?
by Kate Kelland and Genevra Pittman, Reuters, 13 August 2010
Dr. Darrel Francis is the leader of "a study published in the American Journal of Cardiology, [in which] scientists from the National Heart and Lung Institute at Imperial College London calculated that the reduction in heart disease risk offered by a statin could offset the increase in risk from eating a cheeseburger and a milkshake."
Further, "When people engage in risky behaviors like driving or smoking, they're encouraged to take measures that minimize their risk, like wearing a seatbelt or choosing cigarettes with filters. Taking a statin is a rational way of lowering some of the risks of eating a fatty meal."
Discussion
1. Obviously, the above comments and analogies are subject for debate. Defend and criticize the comparisons made.
2. Risk analysis is very much in the domain of statistics. How would you estimate the risk of driving, smoking, eating a cheeseburger or taking a statin? Read the article in the American Journal of Cardiology to see how Francis and his co-authors estimated risk.
3. Pascal’s Wager is famous in religion, philosophy and statistics; his wager is the ultimate in risk analysis.
Historically, Pascal's Wager was groundbreaking as it had charted new territory in probability theory, was one of the first attempts to make use of the concept of infinity, [and] marked the first formal use of decision theory.
The wager is renowned for discussing the risk of not believing in God, presumably the Christian concept of God.
[A] person should wager as though God exists, because living life accordingly has everything to gain, and nothing to lose.
Read the Wikipedia article and discuss the risk tables put forth.
Submitted by Paul Alper
Teaching with infographics
Teaching with infographics: Places to start
by Katherine Schulten, New York Times, The Learning Network blog, 23 August 2010
Each day of this week, the blog will present commentary on some aspect of infographics. Starting with discussion of what infographics are, the series proceeds through applications ranging from sciences and social sciences to the fine arts. Each category will feature examples that have appeared in the Times. The link above for the first day contains an index to the whole series. There is a wealth of material to browse here.
Submitted by Bill Peterson