[Prévia] [Próxima] [Prévia por assunto] [Próxima por assunto]
[Índice cronológico] [Índice de assunto]

Sobre a pesquisa científica (deu na The Economist)

Para os que se interessaram pela noticia do Cribari, seguem os dois artigos relacionados ao assunto. Meu aluno James Dean Oliveira dos Santos Jr escreveu uma nota comentando sobre estes dois artigos (ainda nao publicada) 
Basilio
PS: Boca fechada nao entra mosca nem sai percevejo.
Pior ainda quando se escreve Francisco Cribari Escreveu: 
Fonte:
http://www.economist.co.uk/science/displayStory.cfm?source=hptextfeature&story_id=12376658 
Scientific journals
Publish and be wrong 
Oct 9th 2008
From *The Economist* print edition
One group of researchers thinks headline-grabbing scientific reports are the
most likely to turn out to be wrong 
IN ECONOMIC theory the winner's curse refers to the idea that someone who
places the winning bid in an auction may have paid too much. Consider, for
example, bids to develop an oil field. Most of the offers are likely to
cluster around the true value of the resource, so the highest bidder
probably paid too much. 
The same thing may be happening in scientific publishing, according to a new
analysis. With so many scientific papers chasing so few pages in the most
prestigious journals, the winners could be the ones most likely to oversell
themselves?to trumpet dramatic or important results that later turn out to
be false. This would produce a distorted picture of scientific knowledge,
with less dramatic (but more accurate) results either relegated to obscure
journals or left unpublished. 
In *Public Library of Science (PloS) Medicine*, an online journal, John
Ioannidis, an epidemiologist at Ioannina School of Medicine, Greece, and his
colleagues, suggest that a variety of economic conditions, such as
oligopolies, artificial scarcities and the winner's curse, may have
analogies in scientific publishing. 
Dr Ioannidis made a splash three years ago by arguing, quite convincingly,
that most published scientific research is wrong. Now, along with Neal Young
of the National Institutes of Health in Maryland and Omar Al-Ubaydli, an
economist at George Mason University in Fairfax, Virginia, he suggests why. 
It starts with the nuts and bolts of scientific publishing. Hundreds of
thousands of scientific researchers are hired, promoted and funded according
not only to how much work they produce, but also to where it gets published.
For many, the ultimate accolade is to appear in a journal like *Nature* or *
Science*. Such publications boast that they are very selective, turning down
the vast majority of papers that are submitted to them.
Picking winners 
The assumption is that, as a result, such journals publish only the best
scientific work. But Dr Ioannidis and his colleagues argue that the
reputations of the journals are pumped up by an artificial scarcity of the
kind that keeps diamonds expensive. And such a scarcity, they suggest, can
make it more likely that the leading journals will publish dramatic, but
what may ultimately turn out to be incorrect, research. 
Dr Ioannidis based his earlier argument about incorrect research partly on a
study of 49 papers in leading journals that had been cited by more than
1,000 other scientists. They were, in other words, well-regarded research.
But he found that, within only a few years, almost a third of the papers had
been refuted by other studies. For the idea of the winner's curse to hold,
papers published in less-well-known journals should be more reliable; but
that has not yet been established. 
The group's more general argument is that scientific research is so
difficult?the sample sizes must be big and the analysis rigorous?that most
research may end up being wrong. And the "hotter" the field, the greater the
competition is and the more likely it is that published research in top
journals could be wrong. 
There also seems to be a bias towards publishing positive results. For
instance, a study earlier this year found that among the studies submitted
to America's Food and Drug Administration about the effectiveness of
antidepressants, almost all of those with positive results were published,
whereas very few of those with negative results were. But negative results
are potentially just as informative as positive results, if not as exciting. 

The researchers are not suggesting fraud, just that the way scientific
publishing works makes it more likely that incorrect findings end up in
print. They suggest that, as the marginal cost of publishing a lot more
material is minimal on the internet, all research that meets a certain
quality threshold should be published online. Preference might even be given
to studies that show negative results or those with the highest quality of
study methods and interpretation, regardless of the results. 
It seems likely that the danger of a winner's curse does exist in scientific
publishing. Yet it may also be that editors and referees are aware of this
risk, and succeed in counteracting it. Even if they do not, with a world
awash in new science the prestigious journals provide an informed filter.
The question for Dr Ioannidis is that now his latest work has been accepted
by a journal, is that reason to doubt it? 
--
Francisco Cribari-Neto, cribari@gmail.com,
http://sites.google.com/site/cribari

Attachment: pdfUmmcWDpQz7.pdf
Description: Adobe PDF document

Attachment: pdfIC2JsvGkVc.pdf
Description: Adobe PDF document