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#31
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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
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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 -- -- Lynn Wallace http://www.xmission.com/~lawall "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
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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
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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
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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
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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
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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
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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
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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
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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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