This manuscript attempts to provide the reader with an insight in articial neural networks. Back in 1990, the absence of any state-of-the-art textbook forced us into writing our own. However, in the meantime a number of worthwhile textbooks have been published which can be used for background and in-depth information. We are aware of the fact that, at times, this manuscript may prove to be too thorough or not thorough enough for a complete understanding of the material; therefore, further reading material can be found in some excellent text books such as (Hertz, Krogh, & Palmer, 1991; Ritter, Martinetz, & Schulten, 1990; Kohonen, 1995; Anderson & Rosenfeld, 1988; DARPA, 1988; McClelland & Rumelhart, 1986; Rumelhart & McClelland, 1986).