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Thursday, November 13, 2008

A Computer Model Reproduces Data, It Does Not Provide It

In a January 17, 2003 lecture at the California Institute of Technology (a portion of which was recently reprinted by The Wall Street Journal), Michael Crichton declared:

I take the hard view that science involves the creation of testable hypotheses...

I regard consensus science as an extremely pernicious development that ought to be stopped cold in its tracks. Historically, the claim of consensus has been the first refuge of scoundrels; it is a way to avoid debate by claiming that the matter is already settled. Whenever you hear the consensus of scientists agrees on something or other, reach for your wallet, because you're being had.


Let's be clear: The work of science has nothing whatever to do with consensus. Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right, which means that he or she has results that are verifiable by reference to the real world. In science consensus is irrelevant. What is relevant is reproducible results. The greatest scientists in history are great precisely because they broke with the consensus.

There is no such thing as consensus science. If it's consensus, it isn't science. If it's science, it isn't consensus. Period...


I would remind you to notice where the claim of consensus is invoked. Consensus is invoked only in situations where the science is not solid enough. Nobody says the consensus of scientists agrees that E=mc2. Nobody says the consensus is that the sun is 93 million miles away. It would never occur to anyone to speak that way...

To an outsider, the most significant innovation in the global warming controversy is the overt reliance that is being placed on models. Back in the days of nuclear winter, computer models were invoked to add weight to a conclusion: "These results are derived with the help of a computer model." But now large-scale computer models are seen as generating data in themselves. No longer are models judged by how well they reproduce data from the real world--increasingly, models provide the data. As if they were themselves a reality...

This fascination with computer models is something I understand very well. Richard Feynman called it a disease. I fear he is right. Because only if you spend a lot of time looking at a computer screen can you arrive at the complex point where the global warming debate now stands.

Nobody believes a weather prediction twelve hours ahead. Now we're asked to believe a prediction that goes out 100 years into the future? And make financial investments based on that prediction? Has everybody lost their minds?



What does this have to do with basketball? Some people believe that the sport can be scientifically analyzed by crunching numbers a certain way--but, as Crichton notes, there is a big difference between using a computer model to "add weight to a conclusion" (or, in basketball terms, provide some information about the performance of a player or a team) and using a computer model to "provide the data. As if they were themselves a reality." If you build a computer model of box score data that values rebounding or not turning the ball over or shooting a high percentage and then rank players accordingly, that model will provide some interesting results to consider--but those results are a model; they are not reality and it is possible to tinker with the numbers to produce a another model that will produce completely different rankings. In other words, as I have repeatedly said, Economics is Not a Science, Nor is Basketball Statistical Analysis.

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posted by David Friedman @ 6:30 AM

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Thursday, November 06, 2008

Michael Crichton's Concerns About the State of the Media Today

Michael Crichton, the creator of the TV series "ER" and author of the novels "The Andromeda Strain," "Disclosure" and "Jurassic Park," passed away on Tuesday. A few months before he died, he offered some very insightful comments about the state of the media today:

Michael Crichton: The Decline in Media Quality is a Threat to Freedom

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posted by David Friedman @ 6:35 AM

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