Humans are surrounded by trillions of stimuli. Their eyes, for instance, can discriminate 7,500,000 colors. But, there is a severe limitation in the number of discriminably different stimuli that they can process at one time. George Miller argued that they can handle no more than seven, plus or minus two independent pieces of information at any given time. Thus, necessarily they must develop ways to simplify the task of processing the information that exists in their environment. They do this in many ways. One way is to select the stimuli that are most imp- tant in their lives, what are often...

Humans are surrounded by trillions of stimuli. Their eyes, for instance, can discriminate 7,500,000 colors. But, there is a severe limitation in the number of discriminably different stimuli that they can process at one time. George Miller argued that they can handle no more than seven, plus or minus two independent pieces of information at any given time. Thus, necessarily they must develop ways to simplify the task of processing the information that exists in their environment. They do this in many ways. One way is to select the stimuli that are most imp- tant in their lives, what are often...