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==Forsooth==
----
"There are 33 percent more such women in their 20s than men. To help us see what a big difference 33 percent is,
Birger invites us to imagine a late-night dorm room hangout that’s drawing to an end, and everyone wants to hook up.
'Now imagine,' he writes, that in this dorm room, 'there are three women and two men.'"


[https://quomodocumque.wordpress.com/2015/11/20/imagine-33-percent/ Imagine 33 percent] at Jordan Ellenberg's Quodmodocumque blog (20 November 2015).


Submitted by Priscilla Bremser


==Hot hand, again!==
----
Paul Alper wrote sent a reference to a new post Andrew Gelman's blog: [http://andrewgelman.com/2015/09/30/hot-hand-explanation-again/ Hot hand explanation again] (30 September 2015), which was wriiten to recent news coverage of the hot hand debate:
“I showed all the data together, which helped disguise the bimodal distribution. Nothing wrong with that.
All the data is there. Every piece.... [But then he suggested using] thick and thin lines to try and dress it up,  
or changing colors to divert attention.”


:[http://www.wsj.com/articles/the-hot-hand-debate-gets-flipped-on-its-head-1443465711 The ‘hot hand’ debate gets flipped on its head]<br>
<div align=right>--Bob Schubert (Takata airbag engineer)</div>
:by Ben Cohen, ''Wall Street Journal'', 30 September 2015


The WSJ  gives this description of the key insight in the recent paper ofMiller and Sanjurjo (see [https://www.causeweb.org/wiki/chance/index.php/Chance_News_105#Does_selection_bias_explain_the_.22hot_hand.22.3F Does selection bias explain the "hot hand"?] in Chance News 105) :
quoted in: [http://www.nytimes.com/2016/01/05/business/takata-emails-show-brash-exchanges-about-data-tampering.html Takata emails show brash exchanges about data tampering], ''New York Times'', 4 January 2016
<blockquote>
 
Their [Miller and Sanjurjo's] breakthrough is the surprising math of coin flips. Take the 14 equally likely sequences of heads and tails with at least one heads in the first three flips—HHHH, HTHH, HTTH, etc. Look at a sequence at random. Select any flip immediately after a heads, and you’ll see the bias: There is a 60% chance it will be tails in the average sequence.
Submitted by Bill Peterson
</blockquote>
 
The counterintuitive result comes comes by averaging over sequences rather than over opportunities for a head to follow a head (see [https://www.causeweb.org/wiki/chance/index.php/Chance_News_106#Followup_on_the_hot_hand  this discussion] in Chance News 106 for a detailed comparison of the two averages).
==US Middle-age white mortality==
Here is Gelman's description:
[http://www.economist.com/blogs/graphicdetail/2016/01/daily-chart-22 Contemplating American mortality, again]<br>
<blockquote>
''The Economist'', Daily Chart, 29 January 2016
If you weight by the number of opportunities you indeed get the correct answer of 50% here, but the point is that when the hot hand has traditionally been estimated, the estimation has been done by taking the empirical difference for each player, and then taking a simple (not weighted) average across players, hence the bias, as explained and explored in several recent papers by Josh Miller and Adam Sanjurjo.
 
</blockquote>
[http://andrewgelman.com/wp-content/uploads/2017/04/ageadj.pdf Age-aggregation bias in mortality trends]
The [http://www.sciencedirect.com/science/article/pii/0010028585900106 famous research] in the 1980sby Gilovich, Tversky and Vallone had argued that a shooter's rate of success did not change after a streak of successes.  But if rate was estimated done in the biased way described above, the result should have been lower after a streak.  The fact that it was not would then be evidence of some kind of hot hand phenomenon.  The WSJ quotes statistician Hal Stern: "Almost anyone I’ve interacted with about this [Miller-Sanjurjp] paper has said it’s pretty compelling but the effect is likely small.” 
 
==Tests for gerrymandering==
[http://www.nytimes.com/2015/12/06/opinion/sunday/let-math-save-our-democracy.html?_r=1 Let math save our democracy]<br>
by Sam Wang, ''New York Times'', 5 December 2015


It seems, then, that the debate is not going away anytime soon.  Indeed, we have:
[http://www.washingtonpost.com/wp-srv/special/politics/gerrymandering/ How gerrymandered is your Congressional district?]<br>
by Christopher Ingraham, ''Washington Post'',15 May 2014


:[http://www.nytimes.com/2015/10/18/sunday-review/gamblers-scientists-and-the-mysterious-hot-hand.html Gamblers, scientists and the mysterious hot hand]<br>
appeal to [https://en.wikipedia.org/wiki/Isoperimetric_inequality isoperimetric inequality]: in the plane, a circle maximizes the area of a closed curve with a fixed perimeter.
:by George Johnson, ''New York Times'', 17 October 2015


==Diagnosing disease by smell==
[http://www.economist.com/node/1099030 How to rig an election]<br>
''Economist'', 25 April 2002


Miles Ott sent this link to the Isolated Statsticians list, with the description "A new 'lady tasting tea' example."
"Worst of all is the state's extraordinary 17th District, which is a crab (see chart). Though most of it lies in the western part of the state, two claws stretch out towards the eastern part to grab Democratic cities in order to make the surrounding 18th and 19th districts more reliably Republican."


:[http://www.washingtonpost.com/news/morning-mix/wp/2015/10/23/scottish-woman-detects-a-musky-smell-that-could-radically-improve-how-parkinsons-disease-is-diagnosed/ The amazing woman who can smell Parkinson’s disease — before symptoms appear]<br>
"as used to be said of the old Texas 6th (which was a road from Houston to Dallas), that you could kill most of the constituents by driving down the road with the car doors open."
:by Yanan Wang, ''Washington Post'', 23 October 2015


==Diet science==
==Diet science==
Line 35: Line 46:
by Aaron E. Carroll, “Upshot” blog,  ''New York Time''s, 12 October 2015.  
by Aaron E. Carroll, “Upshot” blog,  ''New York Time''s, 12 October 2015.  


Related “Upshot”:  [http://www.nytimes.com/2015/02/24/upshot/behind-new-dietary-guidelines-better-science.html Behind new dietary guidelines, better science],  February 23, 2015 <>
Related “Upshot”:  [http://www.nytimes.com/2015/02/24/upshot/behind-new-dietary-guidelines-better-science.html Behind new dietary guidelines, better science],  February 23, 2015


==Earthquake prediction==
==Earthquake prediction==
Line 47: Line 58:
"If an earthquake happens in three years, we're both right," Donnellan said.
"If an earthquake happens in three years, we're both right," Donnellan said.
</blockquote>
</blockquote>
USGS https://www.facebook.com/USGeologicalSurvey/posts/955479124498071:0 responded]
==Simulating the lottery==
http://graphics.latimes.com/powerball-simulator/


==Some math doodles==
==Some math doodles==

Revision as of 19:20, 1 February 2016

Forsooth


"There are 33 percent more such women in their 20s than men. To help us see what a big difference 33 percent is, Birger invites us to imagine a late-night dorm room hangout that’s drawing to an end, and everyone wants to hook up. 'Now imagine,' he writes, that in this dorm room, 'there are three women and two men.'"

Imagine 33 percent at Jordan Ellenberg's Quodmodocumque blog (20 November 2015).

Submitted by Priscilla Bremser


“I showed all the data together, which helped disguise the bimodal distribution. Nothing wrong with that. All the data is there. Every piece.... [But then he suggested using] thick and thin lines to try and dress it up, or changing colors to divert attention.”

--Bob Schubert (Takata airbag engineer)

quoted in: Takata emails show brash exchanges about data tampering, New York Times, 4 January 2016

Submitted by Bill Peterson

US Middle-age white mortality

Contemplating American mortality, again
The Economist, Daily Chart, 29 January 2016

Age-aggregation bias in mortality trends

Tests for gerrymandering

Let math save our democracy
by Sam Wang, New York Times, 5 December 2015

How gerrymandered is your Congressional district?
by Christopher Ingraham, Washington Post,15 May 2014

appeal to isoperimetric inequality: in the plane, a circle maximizes the area of a closed curve with a fixed perimeter.

How to rig an election
Economist, 25 April 2002

"Worst of all is the state's extraordinary 17th District, which is a crab (see chart). Though most of it lies in the western part of the state, two claws stretch out towards the eastern part to grab Democratic cities in order to make the surrounding 18th and 19th districts more reliably Republican."

"as used to be said of the old Texas 6th (which was a road from Houston to Dallas), that you could kill most of the constituents by driving down the road with the car doors open."

Diet science

Are fats unhealthy? The battle over dietary guidelines
by Aaron E. Carroll, “Upshot” blog, New York Times, 12 October 2015.

Related “Upshot”: Behind new dietary guidelines, better science, February 23, 2015

Earthquake prediction

Why a 99.9% earthquake prediction is 100% controversial
by Rong-Gong Lin II, Los Angeles Times, 23 October 2015

"This report

Donnellan added that the USGS' 85% probability and her 99.9% chance still favored a big earthquake in the next three years.

"If an earthquake happens in three years, we're both right," Donnellan said.

USGS https://www.facebook.com/USGeologicalSurvey/posts/955479124498071:0 responded]

Simulating the lottery

http://graphics.latimes.com/powerball-simulator/

Some math doodles

<math>P \left({A_1 \cup A_2}\right) = P\left({A_1}\right) + P\left({A_2}\right) -P \left({A_1 \cap A_2}\right)</math>

<math>\hat{p}(H|H)</math>


<math>\hat{p}(H|HH)</math>

Accidental insights

My collective understanding of Power Laws would fit beneath the shallow end of the long tail. Curiosity, however, easily fills the fat end. I long have been intrigued by the concept and the surprisingly common appearance of power laws in varied natural, social and organizational dynamics. But, am I just seeing a statistical novelty or is there meaning and utility in Power Law relationships? Here’s a case in point.

While carrying a pair of 10 lb. hand weights one, by chance, slipped from my grasp and fell onto a piece of ceramic tile I had left on the carpeted floor. The fractured tile was inconsequential, meant for the trash.

BrokenTile.jpg

As I stared, slightly annoyed, at the mess, a favorite maxim of the Greek philosopher, Epictetus, came to mind: “On the occasion of every accident that befalls you, turn to yourself and ask what power you have to put it to use.” Could this array of large and small polygons form a Power Law? With curiosity piqued, I collected all the fragments and measured the area of each piece.

Piece Sq. Inches % of Total
1 43.25 31.9%
2 35.25 26.0%
3 23.25 17.2%
4 14.10 10.4%
5 7.10 5.2%
6 4.70 3.5%
7 3.60 2.7%
8 3.03 2.2%
9 0.66 0.5%
10 0.61 0.5%
Montante plot1.png

The data and plot look like a Power Law distribution. The first plot is an exponential fit of percent total area. The second plot is same data on a log normal format. Clue: Ok, data fits a straight line. I found myself again in the shallow end of the knowledge curve. Does the data reflect a Power Law or something else, and if it does what does it reflect? What insights can I gain from this accident? Favorite maxims of Epictetus and Pasteur echoed in my head: “On the occasion of every accident that befalls you, remember to turn to yourself and inquire what power you have to turn it to use” and “Chance favors only the prepared mind.”

Montante plot2.png

My “prepared” mind searched for answers, leading me down varied learning paths. Tapping the power of networks, I dropped a note to Chance News editor Bill Peterson. His quick web search surfaced a story from Nature News on research by Hans Herrmann, et. al. Shattered eggs reveal secrets of explosions. As described there, researchers have found power-law relationships for the fragments produced by shattering a pane of glass or breaking a solid object, such as a stone. Seems there is a science underpinning how things break and explode; potentially useful in Forensic reconstructions. Bill also provided a link to a vignette from CRAN describing a maximum likelihood procedure for fitting a Power Law relationship. I am now learning my way through that.

Submitted by William Montante