segunda-feira, agosto 23, 2010

Acerca das distribuições e da nossa visão do mundo

  • "The Left-Siders" "The worst part about being a left sider is that it's lonely. There are not that many out there, the majority - the middle of the bell - don't understand you. They can't see what you see. They can't imagine the world you can.

    I have one word of advice for all of you - don't stop. Don't quit. Never give up trying to build the world you can see, even if others can't see it. Listen to your drum and your drum only. It's the one that makes the sweetest sound. And most importantly, when you meet other left-siders, give them a wink, let them know you know...and help them out when they need it.

    The only way the left-siders change the world is when they band together to help each other.

    If you suspect you're a left-sider - email me and let me know the world you imagine. I may know someone who can help you.

    If you suspect you know someone who is a left-sider, stay close to them, protect them and help them. "
  • "The Power of Power Laws" um postal que merece leitura e reflexão profunda. "Here’s the problem (or opportunity). Gaussian distributions tend to prevail when events are completely independent of each other. As soon as you introduce the assumption of interdependence across events, Paretian distributions tend to surface because positive feedback loops tend to amplify small initial events. For example, the fact that a website has a lot of links increases the likelihood that others will also link to this website.

    McKelvey and Andriani suggest that Gaussian distributions can morph into Paretian distributions under two conditions – when tension increases and when the cost of connections decreases. In our globalizing economy, tension rises as competitive intensity increases and as business landscapes evolve faster than the capacity of most organizations to adapt. At the same time, costs of connections are rapidly decreasing as public policy shifts towards freer movement of goods, money and ideas and rapid improvements in the price-performance of IT infrastructures dramatically reduce the cost of information transmission. Bottom line: Paretian distributions become even more prevalent."
  • "Why Gaussian statistics are mostly wrong for strategic organization" e este delicioso trecho "one sees that most of the cases and stories are about extreme events – successes or failures – but seldom about averages. No wonder there is a disjunction: managers live in the world of extremes; researchers using statistics report findings about averages.
    Talk about irrelevant research!
    It is easy for people with no personal experience with an extreme event to think studies of averages are acceptable substitutes."
  • "The Black Swan (Taleb book)" Taleb introduces the concepts of Extremistan and Mediocristan. He uses them as guides to define how predictable is the environment one's studying. Mediocristan environments safely can use Gaussian distribution. In Extremistan environments a Gaussian distribution is used at one's peril."

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