Mostrar mensagens com a etiqueta sensorimotor. Mostrar todas as mensagens
Mostrar mensagens com a etiqueta sensorimotor. Mostrar todas as mensagens

terça-feira, março 18, 2008

Como decidimos o que decidimos (parte II)

"As odd as it may sound, managers make decisions every day that are not based on objective evidence. Instead, they depend heavily on assumptions drawn from the company's collective history or from the industry as a whole. Such conventional wisdom is any idea, notion or rule of thumb that managers apply reflexively and without question. People settle into a particular view of the way their world works; conventional wisdom provides managers with day-to-day guidance.
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When the level of uncertainty spikes - as it would, say, if a manager heard news about an intensifying competitive threat at a key account - it can cause a person to rely more heavily on past experience than on the actual facts. Most people, then, opt for a preprogrammed response fueled by anecdotal evidence. Conventional wisdom can often triumph over objectivity whenever anecdotal evidence seems overwhelmingly convincing.
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(Managers) generalize from single observations, even if the data from thousands of other observations tells them they shouldn't.
We call this the curse of anecdotal evidence.
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managers' decision making derives from a small, selective store of information they continue to accumulate in the same way from the same sources until it lets them down. It becomes their information habit and can prevent them from seeing the obvious, because no one checks or validates old assumptions anymore.
Left unchecked, the resulting conventional wisdom can work as an insidious poison."

Trechos retirados de "Manage for profit, not for market share" de Hermann Simon, Frank Bilstein e Frank Luby.

segunda-feira, março 17, 2008

Como decidimos o que decidimos (parte I)

O JN de hoje traz um interessante artigo "Intuição é fruto da experiência de vida", assinado por
Eduarda Ferreira.
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"Agora, há um grupo de cientistas que vem afirmar que a "pulga atrás do ouvido" tem uma explicação. Afinal, na base desse tipo de decisões, o nosso cérebro nada mais faz do que ir buscar experiências anteriores."
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Não há coincidências, todos os acasos são significativos!
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Ontem veio-me parar ao ecran este artigo:
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"Bayesian decision theory in sensorimotor control" de Konrad P. Kording e Daniel M. Wolpert
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Como é que tudo começou? Quando o organismo unicelular primordial se quis deslocar, para fugir a ser comido, ou para comer, é capaz de ter começado o processo de decisão, o processo mental inicial. E alguma coisa deve ainda estar por cá.
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"The central nervous system (CNS) constantly sends motor commands to our muscles. Determining the appropriate motor command is fundamentally a decision process. At each point in time we must select one particular motor command from the set of possible motor commands. Two components jointly define the decision problem: knowledge of the state of the world (including our own body) and knowledge of our objectives.
The sensory inputs of humans are plagued by noise which means that we will always have uncertainty about our hand’s true location"
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"This uncertainty places the problem of estimating the state of the world and the control of our motor system within a statistical framework. Bayesian statistics provides a systematic way of solving problems in the presence of uncertainty"
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"The approach of Bayesian statistics is characterized by assigning probabilities to any degree of belief about the state of the world.
Bayesian statistics defines how new information should be combined with prior beliefs and how information from several modalities should be integrated. Bayesian decision theory defines how our beliefs should be combined with our objectives to make optimal decisions."
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"The selection of a movement can be described as the rational choice of the movement that maximizes utility according to decision theory"
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"We need to estimate the variables that are relevant for our choice of movement."
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"Bayes rule makes it clear that to perform optimally we must combine prior knowledge of the statistic of the task with the likelihood obtained from the sensory input"