quarta-feira, novembro 19, 2008

Escrita científica

O humour como instrumento de análise da publicação científica:
  • How to write consistently boring scientific literature - Although scientists typically insist that their research is very exciting and adventurous when they talk to laymen and prospective students, the allure of this enthusiasm is too often lost in the predictable, stilted structure and language of their scientific publications. I present here, a top-10 list of recommendations for how to write consistently boring scientific publications. I then discuss why we should and how we could make these contributions more accessible and exciting.
  • Clarity and obfuscation in scientific papers. Scientists are engaged in an endeavor where they're trying to figure out what the data show about the world, not just what they want to see in their experimental results. Ideally, scientists are making sure their data and conclusions can stand up to the toughest objections they can imagine being raised before they even send their manuscripts off to the journal. And, to the extent that science is a knowledge-building project where scientists need to be able to depend on the results communicated by other scientists, they know they should be striving for scrupulous honesty and utter clarity of language.
E, para compensar,

segunda-feira, novembro 10, 2008

quarta-feira, setembro 17, 2008

Mentiras e estatísticas

A conhecida frase de que há mentiras, grandes mentiras, e estatísticas diz mais acerca da natureza humana do que do ramo da Matemática nela mencionado. De facto, uma coisa é estudar estatística e outra é aplicá-la. E o teste t ou a ANOVA, tal como os martelos ou as chaves de fenda, podem ser bem ou mal empregues. A história humana está cheia de boas intenções que deram para o torto- lembro-me disso sempre que há a distribuição dos prémios Nobel. O bom do Alfredo acreditava que o poder da dinamite seria tão destruidor que acabaria com as guerras! E falar de ferramentas neste contexto remete-me também para o discurso brilhante de Ivan Illitch, que tão bem mapeou os limites para além dos quais as ferramentas se tornam elas próprias manipuladoras, um fim em si mesmas.

O magnífico artigo de Nassim TalebTHE FOURTH QUADRANT: A MAP OF THE LIMITS OF STATISTICS, é por isso importantíssimo nos dias de hoje. Ouvi ontem o George Bush, atrapalhado, tentar  justificar perante os americanos a necessidade de usar o seu (dos americanos) dinheiro para salvar da bancarrota os mesmíssimos agentes financeiros que levaram os mercados financeiros à beira da catástrofe. Não sabia era do papel da estatística no meio disto.

Mas este artigo tem várias outras linhas importantes de reflexão. Uma delas tem a ver com análise de riscos perante o desconhecido, que eu ligo às questões relacionadas com as mudanças climáticas actuais. Outra tem a ver com a relação entre redundância e estabilidade, que eu conhecia da ecologia de ecossistemas mas que foi interessante encontrar aqui, num contexto económico e com relevância para febre de redução de pessoal que atravessa agora a Função Pública.

Abri-vos o apetite? Espero que sim.

quarta-feira, julho 09, 2008

Regras simples

Written by PLoS Computational Biology Editor-in-Chief Philip E. Bourne, sometimes with collaborators, the "Ten Simple Rules" provide a quick, concentrated guide for mastering some of the professional challenges research scientists face in their careers.


Ten Simple Rules for Organizing a Scientific Meeting
Corpas M, Gehlenborg N, Janga SC, Bourne PE
Ten Simple Rules for Aspiring Scientists in a Low-Income Country
Moreno E, Gutiérrez J-M
Ten Simple Rules for Graduate Students
Bourne PE, Gu J
Ten Simple Rules for Doing Your Best Research, According to Hamming
Erren TC, Cullen P, Erren M, Bourne PE
Ten Simple Rules for a Good Poster Presentation
Erren TC, Bourne PE
Ten Simple Rules for Making Good Oral Presentations
Bourne PE
Ten Simple Rules for a Successful Collaboration
Vicens Q, Bourne PE
Ten Simple Rules for Selecting a Postdoctoral Position
Bourne PE, Friedberg I
Ten Simple Rules for Reviewers
Bourne PE, Korngreen A
Ten Simple Rules for Getting Grants
Bourne PE, Chalupa LM
Ten Simple Rules for Getting Published
Bourne PE

quinta-feira, junho 26, 2008

Bibliometria


Por cá a bibliometria ainda "só" afecta as avaliações dos centros da FCT, e não sei muito bem como se passam as coisas nas áreas menos propensas a essas contas.


Mas no Reino Unido, onde as questões da avaliação (das pessoas, das instituições, dos produtos e serviços) não são despicientes, a bibliometria vai passar a ter muito peso na renovação de contratos e na progressão na carreira dos docentes universitários.

Vem mesmo a tempo, portanto, o relatório da International Mathematical Union, "Citation Statistics". Transcrevo do sumário, sem mais comentários:

This is a report about the use and misuse of citation data in the assessment of scientific research. The idea that research assessment must be done using "simple and objective" methods is increasingly prevalent today. The "simple and objective" methods are broadly interpreted as bibliometrics, that is, citation data and the statistics derived from them. There is a belief that citation statistics are inherently more accurate because they substitute simple numbers for complex judgments, and hence overcome the possible subjectivity of peer review. But this belief is unfounded.
  • Relying on statistics is not more accurate when the statistics are improperly used. Indeed, statistics can mislead when they are misapplied or misunderstood. Much of modern bibliometrics seems to rely on experience and intuition about the interpretation and validity of citation statistics.
  • While numbers appear to be "objective", their objectivity can be illusory. The meaning of a citation can be even more subjective than peer review. Because this subjectivity is less obvious for citations, those who use citation data are less likely to understand their limitations.
  • The sole reliance on citation data provides at best an incomplete and often shallow understanding of research—an understanding that is valid only when reinforced by other judgments. Numbers are not inherently superior to sound judgments.
[...]We hope those involved in assessment will read both the commentary and the details of this report in order to understand not only the limitations of citation statistics but also how better to use them. If we set high standards for the conduct of science, surely we should set equally high standards for assessing its quality.

segunda-feira, junho 09, 2008

Encontrei um! ENCONTREI UM!


Afinal sempre há economistas ecológicos. Pelo menos um, mas de peso: Herman E. Daly.

Foi economista sénior do Departamento de Ambiente do Banco Mundial, tendo escrito um livro intitulado Steady-State Economics" em 1977 (!). Outros livros cujos título dão uma ideia do seu pensamento incluem Valuing the Earth (1993), Beyond Growth (1996), e Ecological Economics and the Ecology of Economics (1999). Sim, aceito ofertas, e entretanto vou ler os seus artigos. Mas não sem deixar uma figura auto-explicativa dos limites para o crescimento (achei delicioso o futility limit):

terça-feira, junho 03, 2008

O que é ser humano?


Jane Goodall foi enviada para a Tanzânia em 1960 por Louis Leaky, o conhecido paleoantropólogo. Sem nenhuma formação académica relevante (era uma secretária que gostava de animais) esta britânica de 26 anos iria fazer uma série de importantes descobertas que revolucionariam a forma como na altura se perspectivava a posição humana no reino animal.

Até essa altura, a capacidade de construir e utilizar ferramentas era considerada exclusivamente humana, de facto aquilo que separava os humanos dos (restantes) animais. Quando recebeu o relatório em que Jane reportou a sua descoberta de que os chimpanzés usavam ferramentas (preparavam ramos e os utilizavam para extrair térmitas dos seus buracos), Leaky telefonou-lhe:

"Agora temos que redefinir ferramenta, redefinir homem, ou aceitar os chimpanzés como humanos."
E é por esta terceira hipótese que Jane optou, e eu com ela.

Crueldades

Uma horrível descrição de uma cena de caça do século passado, mas que podia ser de hoje se ainda houvesse esta abundância.


Listen to the sensitive but uneducated Bill House [...] talking about what it was like to shoot egrets [garças] for their feathers. Hunters, he tells us, always shot early in the breeding season when the plumes were coming out "real good," and a man with a Flobert rifle could stand in a big rookery and pick off birds as fast as he could reload:

A broke-up rookery, that ain't a picture you want to think about too much. The pile of carcasses left behind when you strip the plumes and move on to the next place is just pitiful, and it's a piss-poor way to harvest, cause there ain't no adults left to feed them young and protect 'em from the sun and rain, let alone the crows and buzzards that come sailing and flopping in, tear 'em to pieces....

It's the dead silence after all the shooting that comes back today, though I never stuck around to hear it; I kind of remember it when I am dreaming. Them ghosty trees on dead white guano ground, the sun and silence and dry stink, the squawking and flopping of their wings, and varmints hurrying in without no sound, coons, rats, and possums, biting and biting, and the ants flowing up all them white trees in their dark ribbons to eat at them raw scrawny things that's backed up to the edge of the nest, gullets pulsing and mouths open wide for the food and water that ain't never going to come. Luckiest ones will perish before something finds 'em, cause they's so many young that the carrion birds just can't keep up. Damn vultures set hunched up on them dead limbs so stuffed they can't hardly fly.

Such a description, quite early in the book, sets the stage for the often senseless and violent deaths to follow, while also registering for our twenty-first-century ears the horror surrounding this steady destruction of a species:

A real big rookery like that one the Frenchman worked up Tampa Bay had four-five hundred acres of black mangrove, maybe ten nests to a tree. Might take you three-four years to clean it out but after that them birds are gone for good.


An Epic of the Everglades
By Michael Dirda

domingo, fevereiro 17, 2008

Cerejas...

Assino (e recomendo!) o The Ecologist. É uma das minhas formas de me lembrar que há coisas bem mais importantes do que as urgências entre as quais saltito de dia para dia.


No número de Fevereiro li uma revisão do livro de Richard Heinberg, "Peak Everything: Waking Up to the Century of Decline in Earth's Resources" e fui à Amazon comprá-lo.

Sim, eu sei, tenho que arranjar uma livraria mais verde! Mas esta tem coisas boas, e uma delas são as sugestões que fazem de outros livros nos quais nós podemos estar interessados. E acertam muita vez.

Como agora: sugeriram-me "World Made by Hand", de James H. Kunstler. Não o comprei (ainda?), mas desde a minha descoberta de Robert A. Heinlein que sei a importância dos ficcionistas com uma mensagem: iluminam-nos o labirinto das possibilidades. E a mensagem do que o petróleo significa no nosso modelo de sociedade, junta com a reflexão sobre o que acontecerá quando ele acabar é, literalmente, de importância vital.

Deixo aqui um excerto de um discurso de Kunstler, na Petrocollapse Conference de 2005:

"We face a series of ramifying, self-reinforcing, terrifying breaks from business-as-usual, and we are not prepared. We are not talking about it in the traditional forums - only in the wilderness of the internet.

Mostly we face a crisis of clear thinking which will lead to further crises of authority and legitimacy - of who can be trusted to hold this project of civilization together.

Americans were once a brave and forward-looking people, willing to face the facts, willing to work hard, to acknowledge the common good and contribute to it, willing to make difficult choices. We've become a nation of overfed clowns and crybabies, afraid of the truth, indifferent to the common good, hardly even a common culture, selfish, belligerent, narcissistic whiners seeking every means possible to live outside a reality-based community.

These are the consequences of a value system that puts comfort, convenience, and leisure above all other considerations. These are not enough to hold a civilization together. We've signed off on all other values since the end of World War Two. Our great victory over manifest evil half a century ago was such a triumph that we have effectively - and incrementally - excused ourselves from all other duties, obligations and responsibilities.

Which is exactly why we have come to refer to ourselves as consumers. That's what we call ourselves on TV, in the newspapers, in the legislatures. Consumers. What a degrading label for people who used to be citizens.

Consumers have no duties, obligations, or responsibilities to anything besides their own desire to eat more Cheez Doodles and drink more beer. (...)

At the bottom of the Peak Oil issue is the fear that we're not going to make it.

The Long Emergency looming before us is going to produce a lot of losers. Economic losers. People who will lose jobs, vocations, incomes, possessions, assets - and never get them back. Social losers. People who will lose position, power, advantage. And just plain losers, people who will lose their health and their lives.

There are no magic remedies for what we face, but there are intelligent responses that we can marshal individually and collectively. We will have to do what circumstances require of us.

We are faced with the necessity to downscale, re-scale, right-size, and reorganize all the fundamental activities of daily life: the way we grow food; the way we conduct everyday commerce and the manufacture of things that we need; the way we school our children; the size, shape, and scale of our towns and cities.
"