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==Chance not in the News==
==Chance not in the News==


Medicine and the Media<br>
In current probability a Martingale is A stochastic process s(0),s(1),s(2),.... with E(s(n+1) = s(n), ie. if it be considered a fair game. With this definition the coin tossing model discussed by Jordon two Martingales, one when you have a finite amount of money and another when you have and unlimited amount of money.  .  Doob proved that if the values s(0), (1),s(2), ... are bound by a number B then for for any stopping rule
Whose watching the watchdogs<br>
Lisa M Schwartz, Stephen Woloshin, Roy Moniham<br>
British Medical Journal, 19 November, 2008<br>


There has been a great deal of concern of bias when a researcher is testing the effectiveness of a new drug and has financial support from the company that produces the drug. In this paper the authors say that we should have the same concerns when news writers report the effectiveness of a new drug produced by a company from which they have had financial rewards.


The authors illustrate the ways that news writers are rewarded by drug companies with the following table:
If s)0),.. is a bounded martingale then and T is a stopping time then the expeked value of S(T) - S(0)
===Additional Reading===


[http://quomodocumque.wordpress.com/2008/10/02/slate-piece-on-martingales-expected-value-and-the-bailout/ Slate piece on martingales, expected value, and the bailout.]


<center> http://www.dartmouth.edu/~chance/forwiki/422.jpg </center>
[http://wizardofodds.com/gambling/bettingsystems.html The Wizard of Oz]


Then they give suggestions how this could be avoided with the following table:
[http://www.iansharpe.com/art_martingale.php Ian Sharpe]
 
 
<center> http://www.dartmouth.edu/~chance/forwiki/423.jpg </center>

Revision as of 02:22, 21 December 2008

Chance not in the News

In current probability a Martingale is A stochastic process s(0),s(1),s(2),.... with E(s(n+1) = s(n), ie. if it be considered a fair game. With this definition the coin tossing model discussed by Jordon two Martingales, one when you have a finite amount of money and another when you have and unlimited amount of money. . Doob proved that if the values s(0), (1),s(2), ... are bound by a number B then for for any stopping rule


If s)0),.. is a bounded martingale then and T is a stopping time then the expeked value of S(T) - S(0)

Additional Reading

Slate piece on martingales, expected value, and the bailout.

The Wizard of Oz

Ian Sharpe