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by Rong-Gong Lin II, ''Los Angeles Times'', 23 October 2015
by Rong-Gong Lin II, ''Los Angeles Times'', 23 October 2015


This [http://geodesy.unr.edu/publications/DonnellanEtAl2015.pdf report]
"This [http://geodesy.unr.edu/publications/DonnellanEtAl2015.pdf report]
<blockquote>
<blockquote>
Donnellan added that the USGS' 85% probability and her 99.9% chance still favored a big earthquake in the next three years.
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.
"If an earthquake happens in three years, we're both right," Donnellan said.

Revision as of 22:35, 25 October 2015


Hot hand, again!

Paul Alper wrote with a reference to the latest on the hot hand from Andrew Gelman's blog: Hot hand explanation again (30 September 2015). In response to this article.

The ‘hot hand’ debate gets flipped on its head
by Ben Cohen, Wall Street Journal, 30 September 2015

The WSJ story is reacting to the recent Miller-Sanjurjo research, and describes the key insight as follows:

You get the non-50% number by first computing the percentage for each scenario, then averaging the 16 scenarios equally. 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.

The ‘hot hand’ debate gets flipped on its head
by Ben Cohen, Wall Street Journal, 30 September 2015
Gamblers, scientists and the mysterious hot hand
by George Johnson, New York Times, 17 October 2015

Blog The hot hand in sports

Diagnosing disease by smell

Miles Ott sent this link to the Isolated Statsticians list, with the description "A new 'lady tasting tea' example."

The amazing woman who can smell Parkinson’s disease — before symptoms appear
by Yanan Wang, Washington Post, 23 October 2015

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.

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