Tuesday, November 22, 2005

Unintended consequences

The story of how NASA missed the detecting the hole in the earth's ozone layer is one of unintended consequences arising from the failure of an information system. NASA had a deployed a sophisticated ozone mapping spectrometer in a satellite called Nimbus-7, which relayed hundreds of data measurements to base on a daily basis. NASA didn't have enough people to process the mass of data and relied on summary indicators.

Unfortunately the spectrometer had been originally programmed to ignore unusually low ozone levels because they had "never happened" previously. The raw data went unchecked until scientists from the British Antartic Survey published details of measurements they had made detecting the thinning of the ozone layer, using old tried and tested instruments.

The trust in the sophistication of the NASA technology combined with the lack of attention to the data generated led to a failure to detect major changes in the system being monitored and a defensive belief, at least initially until they went back and checked the raw data, that their sophisticated technology could not be wrong.

Blunkett, "impossible to fake" and biometric embedded ID cards come to mind, though Mr Blunkett is, of course, no longer in the driving seat on the scheme.

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