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by Aaron E. Carroll, "Upshot" blog, ''New York Times'', 11 May 2015
by Aaron E. Carroll, "Upshot" blog, ''New York Times'', 11 May 2015


Carroll catalogs the large number of studies and meta-analyses showing that moderate coffee consumption is associated with a number of health benefits, this despite a widespread public perception that coffee can't be good for you.
Carroll catalogs the large number of studies and meta-analyses showing that moderate coffee consumption is associated with a number of health benefits, this despite a widespread public perception that coffee can't be good for you.  You can read Carroll's followup to readers's questions about the article [http://www.nytimes.com/2015/05/13/upshot/more-about-coffee-and-health.html?rref=upshot&abt=0002&abg=1 here].


You can read Carroll's followup to readers's questions about the article [http://www.nytimes.com/2015/05/13/upshot/more-about-coffee-and-health.html?rref=upshot&abt=0002&abg=1 here}.
For an earlier discussion
[http://www.nytimes.com/2008/08/05/health/05brod.html Sorting out coffee’s contradictions]<br>
by Jane Brody, ''New York Times'', 5 August 2008


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

Revision as of 15:52, 5 June 2015

Benefits of coffee

Douglas Rogers sent a link to the following:

More consensus on coffee’s benefits than you might think
by Aaron E. Carroll, "Upshot" blog, New York Times, 11 May 2015

Carroll catalogs the large number of studies and meta-analyses showing that moderate coffee consumption is associated with a number of health benefits, this despite a widespread public perception that coffee can't be good for you. You can read Carroll's followup to readers's questions about the article here.

For an earlier discussion Sorting out coffee’s contradictions
by Jane Brody, New York Times, 5 August 2008

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>


KinTape

Ask Well: Does kinesiology tape really work?
by Gretchen Reynolds, "Well" blog, New York Times, 27 March 2015

The technical paper referred to is

Kinesiology tape does not facilitate muscle performance: A deceptive controlled trial
by K.Y. Poon, et.al., Manual Therapy, February 2015 (Vol 20, Issue 1, pp. 130–133)

The sample size started at 46, eventually 30 completed the study; each was blindfolded so that the subjects could not see what kind of taping was done: "Thirty healthy participants performed isokinetic testing of three taping conditions: true facilitative KinTape, sham KinTape, and no KinTape." Here are the ANOVA results for Normalized Peak Torque (NPT), Normalized Total Work (NTW), and Time to Peak Torque (TPT):

All the participants were confirmed to be ignorant about KinTape at the debriefing after the experiment. None of them used KinTape prior to the study and they had never heard of the application of KinTape in any circumstances. NPT, NTW, and TPT in different conditions were shown in Table 1. There was no significant difference in NPT between all three taping conditions at 60° (F(2,87) = 0.05, p = 0.96) and 180°/s (F(2,87) = 0.41, p = 0.66). Similar results were found in NTW (F(2,87) = 0.27, p = 0.76; F(2,87) = 0.53, p = 0.59) and TPT (F(2,87) = 0.03, p = 0.98; F(2,87) = 0.32, p = 0.73) at slow and fast contraction speed respectively.

With such enormously high p-values (correspondingly low F-values) the conclusion is

The present study demonstrated that the KinTape application did not generate higher peak torque, yield greater total work, or shorten time to peak torque in healthy young adults. Positive results in the previous studies of KinTape may be attributed to the placebo effects.

Submitted by Paul Alper

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


The p-value ban

http://www.statslife.org.uk/opinion/2114-journal-s-ban-on-null-hypothesis-significance-testing-reactions-from-the-statistical-arena