The demonstration of a computer is an important event for the computer staff, whether the computer is to be sold or rented, whether it has been constructed by a non-profit organization, or whether it is simply to be used in an industrial or scientific installation. The staff operating a computer in a research, educational, or industrial organization is anxious to impress users of the machine with its speed, flexibility, and large domain of applicability, for it is important that the computer be used to its fullest extent and advantage to justify its considerable cost. Because computer demonstrations are usually made to persons who do not know the inner workings of the device, their impact is generally dependent on an understanding of the psychological attitude of humans towards machines. A machine that acts like a human will, for a little while at least, impress those humans viewing it for the first time.