Although a present-day artificial neural network (ANN) resembles the human
brain much as a paper plane resembles a supersonic jet, it is a big step forward.
ANNs are capable of ‘learning’, that is, they use experience to improve their
performance. When exposed to a sufficient number of samples, ANNs can
generalise to others they have not yet encountered. They can recognise handwritten
characters, identify words in human speech, and detect explosives
at airports. Moreover, ANNs can observe patterns that human experts fail
to recognise. For example, Chase Manhattan Bank used a neural network to
examine an array of information about the use of stolen credit cards – and
discovered that the most suspicious sales were for women’s shoes costing
between $40 and $80.