"The machine could make the toss come out heads every time" Maybe it was just an extended pattern that we all know sometimes occurs in random sequences! lol
--Mike On Mon, Aug 3, 2009 at 4:13 PM, Mike Palij <[email protected]> wrote: > On Mon, 03 Aug 2009 12:54:32 -0700, Christopher D. Green wrote: > >The next time you want to use the coin-flip example in stats class... > >think about this. > > > http://www.thebigmoney.com/articles/hey-wait-minute/2009/07/28/flipping-out?g=1 > > I think the key passage in the article is the following: > > |The physics-and math-behind this discovery are very complex. > |But some of the basic ideas are simple: If the force of the flip is the > |same, the outcome is the same. To understand more about flips, > |the academics built a coin-tossing machine and filmed it using a > |slow-motion camera. This confirmed that the outcome of flips isn't > |random. The machine could make the toss come out heads every time. > > In some respects, this should not be surprising because if the same > amount of force is applied to each toss AND the tossing situation > is a closed system (i.e., limited variation in environmental conditions, > such as constant temperature, wind speed, air pressure, etc.), then > one should have a highly deterministic, mechanistic system -- all third > variables that can affect the outcome are effectively controlled. > Performing > the coin tossing in, say, a hurricaine or near a tornado or on the deck > of ship in a storm at sea, are unlikely to provide such uniform results. > > |When people, rather than a machine, flipped the coin, results were > | less predictable, but there was still a slight physical bias favoring the > |position the coin started in. If the coin started heads up, then it would > |land heads up 51 percent of the time. > > This, too, should not be surprising because it requires a fair amount of > practice in order to do a motor action with little variation (simple RT > shows this). There should be moment-to-moment variations in the > amount of force used in the coin-toss due to random factors (i.e., > changes in attention, motor control, etc) even assuming fixed environmental > conditions (not to mention factors such as drinking Long Island Ice Teas > during the task or playing tetris while flipping the coin). > > So, what is the point? If the amount of force used to flip a coin is > "optimal", a single outcome can be reliably produced (perhaps with > a probability approaching 1.00) under constant environmental conditions. > However, if the amount of force used to flip a coin varies, then the > predictablity of the outcome is reduced. If the amount of force used is > a random variable, then this will reduce the predictably of an outcome. > It probably is more complicated than this but I think this is what allows > one to continue to use the coin toss example (because force varies from > trial to trial in unpredicable ways). > > -Mike Palij > New York University > [email protected] > > > > > > --- > To make changes to your subscription contact: > > Bill Southerly ([email protected]) > --- To make changes to your subscription contact: Bill Southerly ([email protected])
