主题：Nature 道歉了 -- 香山居士

FROM LAI JIANG, Department of Chemistry, University of Pennsylvania

It is a shame to see Nature — which nearly all scientists, including myself, regard as one of the most prestigious and influential physical-science magazines — publish a thinly veiled biased article like this. Granted, this is not a peer-reviewed scientific article and did not go through the scrutiny of picking referees. But to serve as a channel for the general populace to be in touch with and appreciate science, the authors and editors should at least present the readers with facts within the proper context, which they blatantly failed to do.

First, to identify Ye’s performance increase, Ewen Callaway compared her Olympic 400-metre IM time with her performance at the World Championships in 2011 (4:28.43 and 4:35.15, respectively) and concluded that she had an “anomalous” improvement of around 7 seconds (6.72 s). In fact, her previous personal best was 4:33.79 at the Asian Games in 2010. This leads to an improvement of 5.38 seconds. In a sporting event in which 0.1 s can be the difference between the gold and silver medal, I see no reason for 5.38 s to be treated as 7 s.

Second, as previously pointed out, Ye is only 16 years old and her body is still developing. Bettering oneself by 5 seconds over two years may seem impossible for an adult swimmer, but it certainly happens among youngsters. An interview with Australian gold medallist Ian Thorpe revealed that his 400-metre freestyle time improved by 5 seconds between the ages of 15 and 16. For regular people, including Callaway, it may be hard to imagine what an elite swimmer can achieve as he or she matures and undergoes scientific and persistent training. But jumping to the conclusion that it is “anomalous” based on ‘Oh that’s so tough I cannot imagine it is real’ is hardly sound.

Third, to compare Ryan Lochte’s last 50 metres to Ye’s is a textbook example of ‘cherry-picking’ your data. Yes, Lochte was slower than Ye in the last 50 metres, but Lochte had a huge lead in the first 300 metres, so he chose not to push himself too hard and to conserve his energy for later events (whether this conforms to the Olympic spirit and the ‘use one’s best efforts to win a match’ requirement that the Badminton World Federation recently invoked to disqualify four badminton pairs is another topic worth discussing, though probably not in Nature). Ye, on the other hand, was trailing behind after the first 300 metres and relied on freestyle, in which she has an edge, to win the race. Failing to mention this strategic difference, as well as the fact that Lochte is 23.25 seconds faster (4:05.18) than Ye overall, creates the illusion that a woman swam faster than the best man in the same sport, which sounds impossible. Putting aside the gender argument, I believe this is still a leading question that implies to the reader that there is something fishy going on.

Fourth is another example of cherry-picking. In the same event, there are four male swimmers who swam faster than both Lochter (29.10 s) and Ye (28.93 s) in the final 50 metres: Kosuke Hagino (28.52 s), Michael Phelps (28.44 s), Yuya Horihata (27.87 s) and Thomas Fraser-Holmes (28.35 s). As it turns out, if we are just talking about the last 50 metres in a 400-metre IM, Lochter is not the example I would have used if I were the author. What kind of scientific rigorousness is Callaway trying to demonstrate here? Is it logical that if Lochter is the champion, we should assume that he leads in every split? That would be a terrible way to teach the public how science works.

Fifth is the issue I oppose the most. Callaway quotes Ross Tucker and implies that a drug test cannot rule out the possibility of doping. Is this kind of agnosticism what Nature really wants to teach its readers? By that standard, I estimate that at least half of the peer-reviewed scientific papers in Nature should be retracted. How can one convince the editors and reviewers that their proposed theory works for every possible case? One cannot. One chooses to apply the theory to typical examples and to demonstrate that in (hopefully) all scenarios considered, the theory works to a degree, and that that should warrant publication until a counterexample is found. I could imagine that Callaway has a sceptical mind, which is crucial to scientific thinking, but that would be put to better use if he wrote a peer-reviewed paper that discussed the odds of Ye doping on a highly advanced, non-detectable drug that the Chinese have come up with in the past 4 years (they obviously did not have it in Beijing, otherwise why not use it and woo the audience at home?), based on data and rational derivation. This article, however, can be interpreted as saying that all athletes are doping and the authorities are just not good enough to catch them. That may be true, logically, but definitely will not make the case if there is ever a hearing by the governing body for water sports, FINA, to determine if Ye has doped. To ask whether it is possible to obtain a false negative in a drug test looks like a rigged question to me. Of course it is possible: other than the athlete taking a drug that the test is not designed to detect, anyone who has taken quantum 101 will tell you that everything is probabilistic in nature, and so there is a probability that the drug in an athlete’s system could tunnel out right at the moment of the test. A slight chance it may be, but should we disregard all test results because of it? Let’s be practical and reasonable, and accept that the World Anti-Doping agency (WADA) is competent at its job. Ye’s urine sample will be stored for eight years after the contest for future testing as technology advances. Innocent until proven guilty, shouldn’t it be?

Sixth, and the last point I would like to make, is that the out-of-competition drug test is already in effect, which Callaway failed to mention. As noted in the president of WADA’s press release, drug testing for Olympians began at least six months before the opening of the London Olympics. Furthermore, 107 athletes have been banned from this Olympics for doping. That may be the reason that “everyone will pass at the Olympic games. Hardly anyone fails in competition testing” — those who did dope have already been caught and sanctioned. Callaway is free to suggest that a player could have doped beforehand and fooled the test at the game, but this possibility is certainly ruled out for Ye.

Over all, even though Callaway did not falsify any data, he did (intentionally or not) cherry-pick data that, in my view, are far too suggestive to be fair and unbiased. If you want to cover a story of a suspected doping from a scientific point of view, be impartial and provide all the facts for the reader to judge. You are entitled to your interpretation of the facts, and the expression thereof in your piece, explicitly or otherwise, but showing only evidence that favours your argument is hardly good science or journalism. Such an article in a journal such as Nature is not an appropriate example of how scientific research or reporting should be done.