Over the past twenty years, computers and computing technology have become widely disseminated in our society, as increase in efficiency and reductions in size have reduced costs and allowed the introduction of computers for countless thousands of different applications. At a human level, computers have gone from being the instrument of a fairly technically specialized group of workers to a common tool of many different kinds of people. The diffusion of the computer as an “everyday tool” like the telephone or television is not yet fully complete – everyone (or virtually everyone) in the society does not own or use a computer. Nevertheless, computers continue to be more and more integrated into our daily lives, and what was once regarded as science fiction speculation – a computer in every home – is now regarded by many persons a s a logical inevitability.