Chance News 55: Difference between revisions

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==Quotations==
==Quotations==
<blockquote>The typical opinion poll … doesn’t trouble to ask whether the respondent knows the first thing about the topic being opined upon, and no conventional poll disqualifies an answer on the ground of mere total ignorance.  The premise of opinion polling is that people are, and of right ought to be, omni-opinionated – that they should have views on all subjects at all times – and that all such views are equally valid.  ….  So, given the prominence of polls in our political culture, it’s no surprise that people have come to believe that their opinions on the issues of the day need not be fettered by either facts or reflection.  ….  Now there’s the intellectual free lunch:  I’m entitled to vociferous opinions on any subject, without having to know, or even think, about it.</blockquote>
<div align=right>Michael Kinsley, <i>The New Yorker</i>, February 6, 1995</div align=right)>


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Revision as of 12:13, 15 September 2009

Quotations

The typical opinion poll … doesn’t trouble to ask whether the respondent knows the first thing about the topic being opined upon, and no conventional poll disqualifies an answer on the ground of mere total ignorance. The premise of opinion polling is that people are, and of right ought to be, omni-opinionated – that they should have views on all subjects at all times – and that all such views are equally valid. …. So, given the prominence of polls in our political culture, it’s no surprise that people have come to believe that their opinions on the issues of the day need not be fettered by either facts or reflection. …. Now there’s the intellectual free lunch: I’m entitled to vociferous opinions on any subject, without having to know, or even think, about it.

Michael Kinsley, The New Yorker, February 6, 1995

Forsooths

Responding to a Canadian viewer who pointed out that "life expectancy in Canada under our health system is higher than the USA," Fox's Bill O'Reilly on 7/27/09 said,

Well, that's to be expected, Peter, because we have 10 times as many people as you do. That translates to 10 times as many accidents, crimes, down the line.


Breaking News

The Wall Street Journal of September 8, 2009 reports on a study in the Journal of Bone and Joint Surgery: “The researchers compared the outcomes of patients who underwent surgery between 6 a.m. and 4 p.m. for fractures of the femur or tibia to those who had comparable surgeries for similar fractures outside those normal hours.”

Sample

Reoperations

Needed

Sample Size
Sample Proportion
Outside Normal Hours
28
82

.3415

Within Normal Hours
12
70
.1714

The results are:

Difference = p (1) - p (2) Estimate for difference: 0.170035 95% CI for difference: (0.0346494, 0.305420) Test for difference = 0 (vs not = 0): Z = 2.37 P-Value = 0.018

Fisher's exact test: P-Value = 0.026

Discussion

1. Why is the Fisher exact test P-Value (0.026) to be preferred to the other P-Value mentioned (0.018)?

2. The Wall Street Journal mentioned several caveats “making it difficult to determine the underlying reasons for the after-hours patients’ poor outcomes.” List a few practical significance hedges to the statistically significant result.

Contributed by Paul Alper