Clive Holloway introduces the programme from Sussex University. He uses a trick to illustrate the distinction between seeing and perceiving. To highlight this distinction he uses examples of optical illusions, Ames? Trapezoidal Window and the Necker Cube. Next he shows a film clip of Johanson's moving dots. He suggests that this demonstrates how we use schema to build up a pattern of perception from small clues. It is the schema which would need to be put into a computer for it to recognise objects. He defines a schema as a proper description of an object and their proper relationships. Clive next conducts an experiment with two people, to demonstrate the need for precision when making descriptions. One of the volunteers describes a structure of bricks which the other person must then try to build. Clive now demonstrates an artificial intelligence programme which represents schemas of the shapes and relationships of blocks. He rearranges some blocks to make a T shape and lists their properties. He does the same for an arch and shows how this can be represented on a computer. He then shows an unidentified schema would be counted by the computer as 'not an arch? and how the computer can be fooled by a description.