ABSTRACT
Training as used here includes education and also includes teaching them skills such as the ability to diagnose faults and work out the action required, while instructions tell them what they should and should not do. A biologist who has studied the ability of insects to learn writes that this ability has evolved when the environment is too unpredictable for fixed, inborn behaviour patterns to be appropriate. The accident at Three Mile Island nuclear power station in 1979 had many causes and many lessons can be drawn from it, but some of the most important ones are concerned with the human factors. In Melbourne, Australia in 1970, a box girder bridge, under construction across the Yarra river, collapsed during construction. In the summer of 1974, a plastic gas main was laid in a street in Freemont, Nebraska, alongside a hotel, and was fixed to metal mains at each end by compression couplings.
