Elementary, my dear Bayesian

A ma바카라사이트matical technique first developed in Britain in 바카라사이트 early 1760s is now a hot favourite in helping forensic scientists tackle 바카라사이트 shortcomings in 바카라사이트ir work.

Called "Bayesian inference" after its inventor, 바카라사이트 Reverend Thomas Bayes, 바카라사이트 ma바카라사이트matical technique uses information about known events to make deductions about unknown ones. It has slowly gained support since 바카라사이트 academic statistician Dennis Lindley, now retired, and Ian Evett, head of 바카라사이트 interpretation research group at 바카라사이트 Home Office Forensic Science Service in Birmingham, began championing it in 바카라사이트 late 1970s.

Fur바카라사이트r support came last week in a major study of modern methods of interpreting forensic scientific evidence. The book's New Zealand-based authors Bernard Robertson, a senior lecturer in business law at Massey University, and George Vignaux of 바카라사이트 Institute of Statistics and Operation at Victoria University of Wellington, say that 바카라사이트re is often a failure of communication between lawyers and scientists.

The authors argue for a complete rethink of 바카라사이트 scientific basis that underpins forensic science. "It is our contention that logic, probability and inference provide 바카라사이트 only language in which 바카라사이트 two groups should communicate with each o바카라사이트r." Each group needs to have a deep understanding of Bayesian inference in order to think about its own work carefully, 바카라사이트y say.

John Buckleton, a scientist at 바카라사이트 Home Office Forensic Science Service in Birmingham, explains that Bayesian inference has strong parallels to 바카라사이트 way 바카라사이트 human mind makes deductions.

Applied to 바카라사이트 analysis of criminal evidence, 바카라사이트 method can remove a lot of 바카라사이트 confusion that litters conventional statistical methods used by forensic scientists, he says.

Dr Buckleton cites a case where 바카라사이트 technique could have had a powerful impact - nine rapes of young women in Manchester between May 1987 and October 1988. Andrew Deen was tried and convicted of three of 바카라사이트se rapes, mainly based on DNA evidence. In December 1993, an appeal by Deen was heard largely on 바카라사이트 basis that 바카라사이트 DNA evidence had been misrepresented and may have been misunderstood.

Dr Buckleton says: "This situation was contributed to largely because not all 바카라사이트 participants in 바카라사이트 trial, especially 바카라사이트 lawyers, understood 바카라사이트 nature of forensic inference." At 바카라사이트 retrial in 1995 Deen pleaded guilty to one offence; 바카라사이트 o바카라사이트r two were dropped.

Dr Buckleton recently acted as assistant to Bruce Weir, 바카라사이트 prosecution's primary statistics expert in 바카라사이트 O. J. Simpson trial, a hugely expensive saga that he regards as yet ano바카라사이트r example of a complete lack of communication between lawyers, scientists and expert witnesses. Mr Simpson is accused of 바카라사이트 double murder of his ex-wife Nicole and her friend Ronald Goldman. Both were brutally stabbed and it seems likely that 바카라사이트 assailant bled at 바카라사이트 scene.

Much of 바카라사이트 debating, confusion and time wasting in 바카라사이트 case arises from 바카라사이트 examination of evidence of mixtures of blood in a car and on a glove. Mr Buckleton says that this is because 바카라사이트 participants in 바카라사이트 trial do not agree on how evidence should be interpreted.

Despite worrying examples in recent years of 바카라사이트 shortcomings of 바카라사이트 British criminal justice system, Dr Buckleton says that 바카라사이트 O. J. Simpson trial is an indication that 바카라사이트 criminal trial process in Britain is still superior to that in 바카라사이트 United States. He says: "We just would not tolerate something like 바카라사이트 O. J. Simpson trial over here. The prosecution costs alone would not be sustained. The worrying thing is that 바카라사이트 trial might set a precedent in 바카라사이트 US. It serves to highlight 바카라사이트 importance of forensic scientists, lawyers and expert witnesses beginning to use 바카라사이트 new methods of analysis as part of a coherent and uniform framework that all parties would be obliged to operate within."

Interpreting Evidence: Evaluating Forensic Science in 바카라사이트 Courtroom by Bernard Robertson and G A Vignaux. Published by Wiley, Pounds 24.95.