I've upgraded my Thinkbook to Fedora 9. It'll take a while to beat it into submission.

I'm often annoyed by the overuse of the Gaussian (often called Normal) probability distribution in statistics. In The Black Swan Nassim Nicholas Taleb expresses not just annoyance, but outrage, at such usage. He presents a pragmatic and contrarian view of probability and statistics, particularly as they relate to risk and decision analysis. A black swan is a rare, unexpected event that has a large impact. Europeans believed that all swans were white until the first black swan was sighted in Australia.

We never know true probabilities, we can only estimate them using various statistical methods. Using a set of data to estimate the probability of a particular event occurring requires that some probability distribution be used as a model. The Gaussian is often used because it is mathematically tractable and fits some common phenomena. Knowing the mean and variance of a Gaussian is to know the whole distribution. Since probabilities fall off exponentially with distance from the mean, the mean can be, and too often is, treated almost like a constant. Over reliance on the Gaussian causes people to underestimate the likelihood of rare events. When the rare events have major consequences, disastrous decisions often result.

No amount of data can prove that a model is correct, but it only takes one data point to prove it wrong. People often throw out 'outliers' that don't fit the Gaussian model to get a better fit, but this leads to underestimating the true variability and increasing the chance of being blindsided by the unexpected. Games of chance are often used to teach probability theory since they're easy to understand. However, they represent a sanitized and simplified world in which the rules are known and probabilities easily calculated. The real world is messier than that and contains hostile players.

This book is a must read for anyone dealing with risk in the modern world, that is, for everyone. Extreme, rare events aren't really predictable, but one can see possibilities. Since black swans can positive as well as negative, Taleb recommends maximizing exposure to the good black swans and minimizing exposure to the bad ones. Easier said than done .

I flew from Singapore to Colorado yesterday and it's good to be home. I crashed about 20:30 and woke up at 02:30. We went to Boulder for a volunteer shift at the traveling Vietnam Memorial Wall, then church, and catching up a bit around the house.

Our week in Singapore has flown by. Work was busy and there wasn't enough time to see everyone and do everything. Singapore is still one of the nicest cities you'll find anywhere, but more expensive than ever.