ABSTRACT
Human-computer interaction (HCI) is fundamentally an information processing task. In interacting with a computer, the human has specific goals and subgoals in mind. The user initiates the interaction by giving the computer commands that are directed toward accomplishing those goals. The commands may activate software programs designed to allow specific types of tasks, such as word processing or statistical analysis, to be performed. The resulting computer output, typically displayed on a screen, must provide adequate information for the user to complete the next step, or the user must enter another command to obtain the desired output from the computer. The sequence of interactions to accomplish the goals may be long and complex, and several alternative sequences, differing in efficiency, may be used to achieve these goals. During the interaction, the user is required to identify displayed information, select responses based on the displayed information, and execute those responses. The user must search the displayed information and attend to the appropriate aspects of it. She or he must also recall the commands and resulting consequences of those commands for different programs, remember information specific to the task that is being performed, and make decisions and solve problems during the process. For the interaction between the computer and user to be efficient, the interface must be designed in accordance with the user’s information processing capabilities.
