Clive Holloway and Richard Young, from the University of Edinburgh, introduce the programme which is recorded before an invited audience. They attempt to construct a model which can represent human skills, in this case the actions required to fry and egg. Clive shows how these actions could be represented by a flow chart. Following the chart he fries an egg and makes toast. Richard Young now criticises the way in which the flow chart represents human actions as it is too fixed and rigid. He suggests an alternative notation, a production system, which is a selection of rules and conditions. Clive once more fries an egg following the production system. Richard describes how the production system's flexibility improves on the performance of the flow chart. As an example of this we see a rehearsal in which, as Clive is cooking his egg, the toaster catches fire. On the flow chart actions to deal with such an emergency would need to be scattered through the system. For the production system to cope with this all that is needed is the addition of one extra rule and condition. To show the ability of production systems to explain and copy improved behaviour, which may be quantitively different from the initial behaviour, Richard sets up a system for a seriation task. First of all we see some young children carrying out the task. Having discussed their behaviour Richard now shows how his system would operate. Initially his system has no possibility of correcting the line of blocks. By adding one further rule it is possible to complete the seriation task.
Production systems in artificial intelligence are a way of representing the mental processing that may take place when people solve problems. We look in this programme at the operation of a simple production system for a cooking task and compare the use of such a system to a more conventional flow chart. Then we see in some detail how a production system can represent the changing approach of a child to solving a simple problem as he develops mentally. This programme was also recorded at Edinburgh University with the help of a participating audience.