OptiBoard MIAs: Whatever happend to ...

**rinselberg** · 11-13-2006, 05:18 PM

The last time someone started a thread like this it got a little "hairy" - but knowing the risks, I wonder what has become of these OptiBoard members who not so long ago were posting almost every day ... are they now just "lurking" ... will any of them read this? Does anyone reading this happen to be "a friend of a friend" ..? As I peruse their most recent posts, there are no semblances of a leave-taking, and nothing to shine a light on their seemingly unpredicted vanishings from these Alexa-celebrated shores ...

I hope that they found what they perceive as more agreeable posting venues - or happier pursuits, perhaps, than Internet posting.

mirage2k2 ... QDO1 ... spartus ..?

More than just a search for little green men

**Fezz** · 11-13-2006, 05:53 PM

Good idea Rinselberg!

Ok-How about=mrba(Mr. Bad**** if I remember right).

The posts with that character were always entertaining. No matter what you thought of the person, he surely stirred the pot and got us all thinking!

**rinselberg** · 11-13-2006, 05:57 PM

Well Fezz - that's exactly where it got "hairy" the last time around.

I was thinking of OTHER OptiBoard members ...

**Fezz** · 11-13-2006, 06:07 PM

;)

**keithbenjamin** · 11-13-2006, 08:07 PM

Tryin to start sumpthin again, eh Fezz?

Please, don't the shock waves went beyond Optiboad. ;)

LMAO

-Keith

**Snitgirl** · 11-13-2006, 08:43 PM

Originally Posted by Fezz

;)

Fezz, always getting your hands dirty.... hehehe

**mirage2k2** · 11-14-2006, 01:46 AM

I'm alive :)

just not allowed to post anywhere about anything useful anymore.

**rinselberg** · 11-14-2006, 02:03 AM

Picking up right where I stopped, it's surprising how many people, including trained mathematicians and scientists, have been observed to get this wrong. It's said to be "counter-intuitive". I have to say that when I caught this on The Science Channel a few weeks ago, it tricked me into a wrong answer. Of the three OptiBoard members who sent me a PM, all three got it right. I would call that "sampling bias".

Speaking for the "dummies", what tends to flash into our minds (or is it their minds ..?) is this: It's down to just two cards - the one that you selected - which is still face down - and the other card that's still face down. That makes it even odds whatever you do. Since you cannot better your odds by switching, you may just as well play the card that you already selected - always.

And where does that get us?

Odds of winning: One chance in three.

But there's a better strategy. In fact, there's a perfectly optimal strategy. To wit: Always renege and play the last remaining card, instead of the card that you selected, and you double your odds of winning to ... two chances in three.

It's the same as if the computer were programmed to respond to your selection - Left, Center or Right - by offering you the option to renege and exchange that one card for both of the other cards. Doesn't framing it like this make the answer obvious?

Or you could look at it this way: Before the computer responds, there is one chance in three that you selected the Joker. There are two chances in three that the Joker is one of the other cards - one of the two that you didn't select.

Then the computer faces a loser from one of the two cards that you didn't select.

Does this add anything to what you know about the card that you selected?

The answer - and this is what has been observed to trip up a surprising number of people - is no.

Regardless of how the cards were dealt, the computer is always going to show you a loser from the two cards that you didn't select. It doesn't make any difference which of the two cards are faced: In either case, you have not been given any additional information about the card that you selected. And so the odds that you selected the Joker are unchanged - still just one chance in three - exactly as they were before your selection.

But what about the cards that you didn't select? There's only one of these cards left in play. And now it's the only alternative to the card that you selected. The odds that this card is the Joker, v. the card that you selected, are - by process of elimination, v. the card that you selected ... two chances in three.

The trick is to realize that when the computer faces one of the two cards that you didn't select, it is only revealing additional information about the two cards that you didn't select.

Another way to analyze it is with a tabular approach. Here the card values are tabularized as Left, Center and Right. Let's assume that you start by selecting the card on the Left. This table reveals all possible outcomes - win or lose - if you play the card that you selected ... the card on the Left :

Joker | Loser | Loser | -> win
Loser | Joker | Loser | -> lose
Loser | Loser | Joker | -> lose

Your odds of winning are one in three.

What happens if you switch (renege) and play the last remaining card?

Joker | Loser | Loser | -> lose
Loser | Joker | Loser | -> win
Loser | Loser | Joker | -> win

Your odds of winning are two in three.

Can you see any reason why you woudn't get the same results, regardless of which card - Left, Center or Right - you initially selected?

Tabular solution; credit: Alvaro Cordova of OpticiansFriend

If these explanations still leave a certain fogginess in some of our heads, it's because this is an exercise in conditional probability - a subject better suited for discourse using the precision language of mathematicians. Enter one Thomas Bayes, a Scottish-educated Presbyterian minister and something of a mathematician - enough to have been named a Fellow of the Royal Society in 1742. The posthumous publication (1764) of "Essay Towards Solving a Problem in the Doctrine of Chances" laid the groundwork for what became known as Bayes' theorem - and that laid the groundwork for the thoroughly modern disciplines of Bayesian probability and statistics.

If you would like to read more about this subject online, you could start with the Wikipedia's Monty Hall paradox, which takes its name from the first and most celebrated host of the long running TV game show "Let's Make a Deal".

The truly mathematical among us - and you can be sure that I am not such company - may find even more entertainment in one of the reports that I used for background:

Quantum Physics: The Quantum Monty Hall Problem
D'Ariano, Gill, Keyl, Kuemmerer, Maassen and Werner
full text available online

We consider a quantum version of a well-known statistical decision problem, whose solution is, at first sight, counter-intuitive to many. In the quantum version a continuum of possible choices (rather than a finite set) has to be considered. It can be phrased as a two person game between a player P and a quiz master Q. Then P always has a strategy at least as good as in the classical case, while Q's best strategy results in a game having the same value as the classical game. We investigate the consequences of Q storing his information in classical or quantum ways. It turns out that Q's optimal strategy is to use a completely entangled quantum notepad, on which to encode his prior information.

A quantum entangled notepad - now why didn't I think of that!

**CME4SPECS** · 11-14-2006, 02:14 AM

What ever happened to Jeff Trail? Optiboarder of the year a few years back.

**Fezz** · 11-14-2006, 06:19 AM

Originally Posted by Snitgirl

Fezz, always getting your hands dirty.... hehehe

At least I wash them.....often! ;)

**Fezz** · 11-16-2006, 09:33 AM

Here is another one(trying to redeem myself after my first attempt;) ):

Jason Cruthers(sp?). He was an active member from Canada with some very insightful posts. I think he changed his screen name and tried some kind of self promotion for a new venture. Did he get banned or moved on to another name?

**ziggy** · 11-16-2006, 12:17 PM

Originally Posted by CME4SPECS

What ever happened to Jeff Trail? Optiboarder of the year a few years back.

Didnt he sell his lab in FL and move to WV, OH or something?

**OPTIDONN** · 11-16-2006, 12:40 PM

Originally Posted by Fezz

Here is another one(trying to redeem myself after my first attempt;) ):

Jason Cruthers(sp?). He was an active member from Canada with some very insightful posts. I think he changed his screen name and tried some kind of self promotion for a new venture. Did he get banned or moved on to another name?

Jason came back briefly as Marketometry. Now I don't know where he is.

**karen** · 11-17-2006, 12:29 PM

Where did Maria go?

**Jacqui** · 11-17-2006, 01:23 PM

Originally Posted by karen

Where did Maria go?

I was wondering about her too

**Steve Machol** · 11-17-2006, 01:25 PM

I miss Maria the most. She has a wonderful and wicked sense of humor. :)

**hcjilson** · 11-17-2006, 03:42 PM

Me too! No disrespect meant to the others.......hj

**Joann Raytar** · 11-18-2006, 12:50 AM

Me three. I always enjoyed waiting to see what Maria would chime in with. I miss John R as well.

**Billy Brock** · 11-19-2006, 08:56 AM

hello all,

MRBA is working his bad *** off ...... staying really busy in the lab

Texas Ranger sold his business and moved to the northwest........ (New Hampshire ?)

they both were always good for a jolt LOL :)

BB

**Jeff Trail** · 11-21-2006, 09:26 AM

:) I am still here, just been moving around a lot, now that I am settled in Chattanooga TN. I will have more time to play.. I'm the new G.M. for Southern here in Chattanooga. Back where I have the most fun..resin and polish pumping through ya...something about AR chambers, to clean and silent that makes you miss running production..
Shoot and I missed bashing all those republicans this last election

Jeff"ahh the smell of alloy in the morning better than starbucks"Trail

**Fezz** · 11-21-2006, 09:48 AM

Thanks Jeff!
Glad to hear things are working out.

:cheers: :cheers:

**hcjilson** · 11-21-2006, 10:21 AM

I did hear from Maria about 3 or 4 months ago, and she does check in from time to time. If memory serves, she has a birthday this month. I won't let my wife retire my Maria's Lilac Optiboard shirt because I think of her when I wear it.....but its long past time for the shirt to go. Sue doesn't even want me to wear it mowing the lawn! :):)

**Steve Machol** · 11-21-2006, 11:25 AM

Hey Jeff! Nice to hear from you again. :)

**Fezz** · 11-21-2006, 04:56 PM

How about = Susan Henault.

She was a lens rep for Shamir, then I believe she went to Essilor?

**Maria** · 10-10-2007, 04:35 PM

I'm still around! Have much less time on my hands than in days of yore, studying for contact lens certificate and working.
It's nice to see all the old familiar names though. Think I feel a poll coming on.......:D