Communicating with a computer using natural language is an appealing idea. Although it is technically very difficult to program a computer to converse intelligently across a variety of domains, it is much easier to program one to understand commands in a restrictive environment. Before the currently-ubiquitous graphical interfaces were popular, Lotus marketed a spreadsheet program that allowed people to communicate with the program using a restricted natural language interface. The program understood commands such as "Project at 10% across" or "Erase all" and, based on the context in which they occured, carried them out appropriately.
Despite the intuitive appeal of a natural language interface, some researchers have argued that a language like English has too many ambiguities to be useful for communicating with computers. Indeed, there is little experimental data supporting the efficacy of a natural language interface, and the few studies that have compared natural language interfaces to other styles of interface have been generally negative.
This study compared the ease of learning a traditional command/menu interface to a spreadsheet with the ease of learning the natural-languge interface of Lotus HAL.