Monday, November 26, 2012

What I've Been Reading

The Signal and the Noise: Why So Many Predictions Fail-but Some Don't by Nate Silver. Silver is one of those people who has given immense hope to the future of AI in abstract fields as politics; cannot think of better person to gauge the present and future of AI in predicting earthquakes to economic growth. The book is packed with information and demolishes any preconceived notions (your weatherman is not a moron) - A must read!!

"Distinguishing the signal from the noise requires both scientific knowledge and self-knowledge: the serenity to accept the things we cannot predict, the courage to predict the things we can, and the wisdom to know the difference."

The Noise:
  • Men may construe things after their fashion / Clean from the purpose of the things themselves,” Shakespeare warns us through the voice of Cicero— good advice for anyone seeking to pluck through their newfound wealth of information. It was hard to tell the signal from the noise. The story the data tells us is often the one we’d like to hear, and we usually make sure that it has a happy ending.
  • We face danger whenever information growth outpaces our understanding of how to process it. Data-driven predictions can succeed— and they can fail. It is when we deny our role in the process that the odds of failure rise. Before we demand more of our data, we need to demand more of ourselves.
  • The problem, Poggio says, is that these evolutionary instincts sometimes lead us to see patterns when there are none there. “People have been doing that all the time,” Poggio said. “Finding patterns in random noise."
  • We need to stop, and admit it: we have a prediction problem. We love to predict things— and we aren’t very good at it.
  • The most calamitous failures of prediction usually have a lot in common. We focus on those signals that tell a story about the world as we would like it to be, not how it really is. We ignore the risks that are hardest to measure, even when they pose the greatest threats to our well-being. We make approximations and assumptions about the world that are much cruder than we realize. We abhor uncertainty, even when it is an irreducible part of the problem we are trying to solve.
  • Our brains, wired to detect patterns, are always looking for a signal, when instead we should appreciate how noisy the data is.
The Signal:
  • It is forecasting’s original sin to put politics, personal glory, or economic benefit before the truth of the forecast. Sometimes it is done with good intentions, but it always makes the forecast worse. The Hurricane Center works as hard as it can to avoid letting these things compromise its forecasts. It may not be a concidence that, in contrast to all the forecasting failures in this book, theirs have become 350 percent more accurate in the past twenty-five years alone.
  • It’s easy for climate systems, if they want to see what’s happening in the atmosphere, they just have to look up. We’re looking at rock. Most events occur at a depth of fifteen kilometers underground. We don’t have a hope of drilling down there, realistically— sci-fi movies aside. That’s the fundamental problem. There’s no way to directly measure the stress. Without that theoretical understanding, seismologists have to resort to purely statistical methods to predict earthquakes. Even if we had a thousand years of reliable seismological records, however, it might be that we would not get all that far. It may be that there are intrinsic limits on the predictability of earthquakes.
  • Economics is a much softer science. Although economists have a reasonably sound understanding of the basic systems that govern the economy, the cause and effect are all blurred together, especially during bubbles and panics when the system is flushed with feedback loops contingent on human behavior.
  • Mathematics classrooms spend more time on abstract subjects like geometry and calculus than they do on probability and statistics. In many walks of life, expressions of uncertainty are mistaken for admissions of weakness.
  • You will need to recognize that there is wisdom in seeing the world from a different viewpoint. The more you are willing to do these things, the more capable you will be of evaluating a wide variety of information without abusing it.
We have big brains, but we live in an incomprehensibly large universe. The virtue in thinking probabilistically is that you will force yourself to stop and smell the data— slow down, and consider the imperfections in your thinking. Over time, you should find that this makes your decision making better.






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