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Tyler Takes An IMAX Hit



 
 
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  #31  
Old March 2nd 05, 05:49 PM
gym gravity
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MagillaGorilla wrote:

Kurgan Gringioni wrote:

Ewoud Dronkert wrote:

On Tue, 01 Mar 2005 15:48:16 GMT, B Lafferty wrote:

Don't forget Santi Perez's two positives. If they're all false



positives,

that makes five from two guys on one team. What are the odds?


We don't know, because there is nothing published on false positive



(or

false negative for that matter) rates for this test.






Let's say that all the tests are false positives.

What are the odds that the *only two* riders to get the false positive
are teamates and roomates?

Let's say 500 riders were tested. Two false positives make the rate 1
in 250.

Then those two get tested again. They both test positive *again*.

The odds of that happening are 250^4 = 3,906,250,000

about one in 4 billion. Then factor in the fact that they're roomates.
Multiply the 4 billion by 499.

1 in 2 trillion.

Poor Tugboat.



K. Gringioni.



Ahh. nope..the false positive rate is nothing of that magnitude if it's
linked to specific types of anitgens that only Perez and Hamilton have
in their blood.

They would always test positive.

Magilla

Perez and Hamilton are both living halves of vanished twins?
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  #32  
Old March 2nd 05, 06:48 PM
Raptor
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Robert Chung wrote:
Kurgan Gringioni wrote:

Such as?



Well, the obvious one is the one you're thinking of: that there was an
organized blood doping program. That's the one I lean towards, too. But,
remember, I get paid high in the three figures to worry about non-obvious
sources of systematic bias. That's part of what goes into proper vetting.


Whoa. That's like $999. 11 of those and you can get:

http://www.cyclingnews.com/tech.php?...005/news/03-02

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"We should not march into Baghdad. ... Assigning young soldiers to
a fruitless hunt for a securely entrenched dictator and condemning
them to fight in what would be an unwinnable urban guerilla war, it
could only plunge that part of the world into ever greater
instability." George Bush Sr. in his 1998 book "A World Transformed"

  #33  
Old March 2nd 05, 07:00 PM
Kurgan Gringioni
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Robert Chung wrote:
Kurgan Gringioni wrote:
Seriously, what's a potential systemic bias in this case? I'm

curious
what that may be.


I emphasize that I don't know about this particular case but, in

other
particular cases I've examined, systematic bias can arise because

tests
were done in the same place by the same people with the same

equipment.
This type of bias sometimes happens when there are a very limited

number
of places where something is performed, or a limited number of

examiners
who were all trained in the same place. Sometimes people see what

they
expect to see (we could name some rbr'ers who fall into that

category);
sometimes this happens innocently. Here's a kinda innocent way that

things
can get biased: suppose, for example, 1) blood doping is pretty

evenly
spread across the peloton; 2) experts at the technique are better at
recognizing blood doping than novices; and 3) when a case happens to

be
sensitive it gets shunted up to an expert (this appears to be what
happened at the Olympics, and Dick Pound suggested that Hamilton's

Vuelta
tests were scrutinized exactly because of the Oly results). Now

suppose
samples from teammates of the suspected blood doper are considered to

be
sensitive, and thus also get shunted to experts (it needn't be the

same
expert, just to another expert who has a higher detection rate than a
novice). You would tend to see more doping than the overall rate

based on
the experts' analyses, but you'd also see less doping than the

overall
rate based on the novices' analyses.




Dumbass -

I don't see how the above would make it more likely that two roomates
would be the only two "false positives".

thanks,

K. Gringioni.

  #34  
Old March 2nd 05, 07:01 PM
Kurgan Gringioni
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Tom Kunich wrote:


Robert, you're wasting your time arguing with Henry.





Moron -

Unlike any exchange that you're involved with, we're not arguing, we're
having a rational discussion.

  #35  
Old March 2nd 05, 08:31 PM
Robert Chung
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Kurgan Gringioni wrote:

I don't see how the above would make it more likely that two roomates
would be the only two "false positives".


Sigh. I haven't been talking about false positives. You asked for an
example of how systematic bias could affect the chance that teammates
would be observed to test positive while others don't, not that they would
be false positives.



  #36  
Old March 2nd 05, 08:36 PM
Kurgan Gringioni
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Robert Chung wrote:
Kurgan Gringioni wrote:

I don't see how the above would make it more likely that two

roomates
would be the only two "false positives".


Sigh. I haven't been talking about false positives. You asked for an
example of how systematic bias could affect the chance that teammates
would be observed to test positive while others don't, not that they

would
be false positives.




Dumbass -

I may not have used the correct terminology but the intent was to
inquire about "false positives".

I understand now.


K. Gringioni.

  #37  
Old March 2nd 05, 08:56 PM
Robert Chung
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Kurgan Gringioni wrote:
I may not have used the correct terminology but the intent was to
inquire about "false positives".


Oh, that's much simpler. Just get the guys who were convinced there were
WMDs in Iraq to look at Hamilton's blood. Those guys can see stuff no one
else can.


  #38  
Old March 3rd 05, 05:17 AM
Tom Kunich
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"Kurgan Gringioni" wrote in message
oups.com...

Tom Kunich wrote:
Robert, you're wasting your time arguing with Henry.


Unlike any exchange that you're involved with, we're not arguing, we're
having a rational discussion.


Nice juxtaposition there - Henry and "rational".


  #39  
Old March 4th 05, 07:35 AM
Stewart Fleming
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B Lafferty wrote:

Don't forget Santi Perez's two positives. If they're all false positives,
that makes five from two guys on one team. What are the odds?


As Richard Feynman used to say in return..."When I walked in here
tonight, I saw the license plate (insert banal sounding plate number
here). What are the odds?"
  #40  
Old March 5th 05, 12:16 AM
William H. O'Hara, III
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I was scared when I read that the
lab had to be persuaded to change
the report to FAULTY.

I read this in Velonews.

Bill
 




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