Although conversational systems broadened the accessibility of computers, they still fell far short of the goal of making computers accessible to a large segment of the populace. As conversational interaction grew from slow (10 or 30 character per second) terminals, the appearance of fast alphanumeric terminals (1000 characters per second and up) made it possible to present large amounts of information to the user almost instantaneously. This allowed the computer to present the user with a ``menu'' of choices, from which selections could be made simply by pressing one or two keys.
Menu command selection, coupled with data entry modeled on filling in a form, rapidly became the standard for application systems intended to be operated by non-computer-specialists. Hundreds of thousands of people spend their entire working day operating systems of this design, although people who have studied how users actually learn and use these systems, in applications ranging from credit card transaction entry to targeting tactical nuclear weapons, often find that users see them in a very different way than the designers intended--frequently moving from menu to menu by rote learning of keystroke sequences, leaving the carefully-crafted menus unread.
Many attempts have been made to expand menu-driven systems into a general method of operation. Much of the Macintosh interaction model is actually fourth generation operation. Selecting commands from menus (whether presented directly to a user or pulled down from the top of the screen) and selecting options and setting program parameters by entering them in a form called a ``dialogue box'' is pure fourth generation design. The major point of departure from classic fourth generation structure in the Macintosh menu system is its attempt to place the user in direct command rather than treat the user as a peripheral who directs the computer as so many menu driven application systems do.
Editor: John Walker