Letters
Never blindly trust computer data The tragic case shown in last week’s BMV of faulty software the results from which were misinterpreted by Post Office Ltd must rank amongst other misuses of computers which have taken place over a long time. About 50 years ago computers came into widespread use at university level when data quality, correct parameterisation, and the tedious process of working through the program by hand, in order to remove any bugs. When a computer program, especially a model, is used for prediction, rigorous testing must take place or else the risk of big errors cannot be ruled out. If a program produces a significant correlation coefficient careful experiments are needed to justify a cause effect relationship. However careful the worker may be misinterpretation of results is a common mistake. Having carried out nearly 50 years’ scientific research, and been a reviewer for nine scientific journals I now present a short list of scientific failures which have had serious consequences. First, in October 1987 a forecaster dismissed the question a viewer raised regarding an impending ‘hurricane’, only to find a few hours later, wholesale damage in much of southern England. Apparently, as an economy measure, a weather ship had been closed down and if operational would have greatly improved the forecast. Second, in 1990 it was predicted that the burning of oil wells in Kuwait would cause the Indian Monsoon to fail with disastrous results: in reality nothing happened. Third, in 1999 research at Imperial College London predicted that there would be about half a million deaths caused by BSE. In fact the value was fewer than 200, but the effect on the beef industry was catastrophic. Fourth, two years later work by the same people produced computer-based predictions of
Cartoon by Lyndon Wall justsocaricatures.co.uk
how foot and mouth disease would spread across Britain: this resulted in the slaughter of about 8 million head of mainly healthy cattle. At least one farmer took DEFRA (then MAFF) to court in the hope of saving his herd: he won his case. Fifth, the tragic case of a family whose mother was sent to jail following two cot deaths was based on the joint probability theory being misapplied as prima facie evidence for a verdict of guilty. Such an approach assumes that there was no other possible cause, yet it is known that several other fatal genetic defects can occur in the same family. I could give other examples. Scientific research is difficult to do well, needing patience, determination, total objectivity, intuition, and a lot of hard work. Even that may not be enough because the resulting report must pass the peer review process, which can be far from objective. When a new result is produced and is at odds with an established one there can be both opposition and fear all at once. Computers have made possible difficult
and tedious calculations in a split second. Displayed on a screen the effect can be spellbinding. But how do we know what is being shown is right? The public understanding of science needs vast improvement. Practical studies in most subjects would be a good start, which would bring back the real meaning of design, measurement, size, shape, and application. This is a far cry from the fantasy world of the computer and television screen and might just avoid another computer-based tragedy in the future. Dr Colin Clark n It amazes me that otherwise intelligent people, such as those who run Post Office Ltd, should put such blind faith in computers. The Yetminster postmistress has had her life ruined by this, (NBV, April 30). She was innocent of the charges against her yet Post Office Ltd continued for years to defend its defective computer software. If this is the future it frightens me. Hilary Townsend Stalbridge
n On Apr 20 South Somerset district council approved a major development in Wincanton for housing and employment. Nothing strange in that. What was strange was the officer’s report, which stated that Wincanton was one of the few areas in the district that does not fall within the catchment area of the Somerset Levels. That was a pointless remark, as the sewage and drainage would have to flow uphill to join the levels catchments area. Rainwater, and the sewage works outfall go in to the River Cale, which flows down the Blackmore Vale and joins the River Stour catchments, or so I thought. Clearly we have Central Government control with outreach offices in Dorset, Somerset, and Wiltshire, each with their area of control defined. This has all the appearance of a 1930s totalitarian government and the inevitable disastrous results. Nature is simple but all powerful and its reactions are brutal. We will only succeed if we work with nature, not against nature, and at a realistic level. International conferences do not solve environmental problems; they are solved by truthful work at street level, not box ticking at government level. We are at the tipping point in environment protection, and pointless comments and failure to face the actual pollution problem will not solve anything. Pollution of our rivers is real, and there for all to see, what is required is the commitment to solve the problem by all levels of government. The survival of future generations depends on how we react now, and how we solve a huge economic problem. It will only work with local knowledge, not the usual Westminster computer programme. Colin Winder, Wincanton Ward Member South Somerset District Council 39
