2.1 Four Information Levels

Advanced information systems are sometimes described as intelligent . Just what intelligence is, and whether machines will ever be intelligent, are debatable questions. In the classic Turing Test of intelligence, an opaque screen is placed between a typical human and the object being tested for intelligence (see Figure 2.1). The human can communicate with the object only by means of computer (with keyboard for input and screen for output). The human may communicate in natural language about any desired topic. According to Turing, if the human can t tell from the object s responses whether it is an intelligent human or a machine, then the object should be classified as intelligent. To date, no machine has passed the Turing Test.

Figure 2.1: The Turing Test: can A distinguish between B and C?

Two key conditions in the test are that natural language be used and that there be no restrictions on the topics chosen for discussion. Once we place restrictions on the language and confine the discussion to a predefined topic, we can find examples where a computer has performed at the level of a human expert (e.g., chess, diagnosis of blood diseases, mineral exploration). Such systems are called expert systems since they perform as well as a human expert in some specific domain of application. Expert systems have passed restricted Turing Tests specific to particular universes of discourse.

Expert systems use sophisticated programs, often in conjunction with large but highly specific databases. A fifth-generation information system (5GIS)...