Pages

Saturday, May 08, 2004

Unreasonable faith in modeling makes us burn witches. Of earthquakes and spam.

As some of you know, the team working with Keilis-Borok has ascertained that an earthquake of magnitude larger than 6.5 would hit Southern California before September 5th of this year. Their modeling has many parameters but they show that variation in these parameters still provide a way of devising earthquakes with a high certainty (only one false alarm out of five earthquakes.) For those of us not entirely convinced, they used the algorithm on Italian Earthquakes from 1979 to 2001. The pictures are overall pretty compelling as can be seen here in the map pictures all the way down below. The only miss seems to have been the Assisi earthquake that was categorized as a 6+ magnitude earthquake but predicted by the M8 algorithm to be only a 5.5. The worst that can happen is really if this is a false alarm, a situation not unlike that found for spam filters. In the fight against spam, everybody wants to have a spam filter that does not discard any E-mail that is genuine. Customers for spam filters expect a 100 % accuracy there. They can deal with spam coming through to their mailbox but absolutely do not want real E-mails to not make it to their computers. In the earthquake situation, people can deal with a model that cannot predict an earthquake but they absolutely cannot deal with a false alarm because it takes faith away from the algorithm altogether.

No comments:

Post a Comment