no
P H V S i C S OF THE IMPOSSIBLE
THE TOP-DOWN
APPROACH
There are at least two major problems scientists have been facing for
decades that have impeded their efforts to create robots: pattern recognition and common sense. Robots can see much better than we can,
but they don't understand what they see. Robots can also hear much
better than we can, but they don't understand what they hear.
To attack these twin problems, researchers have tried to use the
"top-down approach" to artificial intelligence (sometimes called the
"formalist" school or GOFAI, for "good old-fashioned AI"). Their goal,
roughly speaking, has been to program all the rules of pattern recognition and common sense on a single CD. By inserting this CD into a
computer, they believe, the computer would suddenly become selfaware and attain humanlike intelligence. In the 1950s and 1960s great
progress was made in this direction, with the creation of robots that
could play checkers and chess, do algebra, pick up blocks, and so forth.
Progress was so spectacular that predictions were made that in a few
years robots would surpass humans in intelligence.
At the Stanford Research Institute in 1969, for example, the robot
SHAREY created a media sensation. SHAREY was a small PDP computer placed above a set of wheels with a camera on top. The camera
was able to survey a room, and the computer would analyze and identify the objects in that room and try to navigate around them. SHAREY
was the first mechanical automaton that could navigate in the "real
world," prompting journalists to speculate about when robots would
leave humans in the dust.
But the shortcomings of such robots soon became obvious. The
top-down approach to artificial intelligence resulted in huge, clumsy
robots that took hours to navigate across a special room that contained
only objects with straight lines, that is, squares and triangles. If you
placed irregularly shaped furniture in the room the robot would be
powerless to recognize it. (Ironically, a fruit fly, with a brain containing only about 250,000 neurons and a fraction of the computing power
of these robots, can effortlessly navigate in three dimensions, execut-
P H V S i C S OF THE IMPOSSIBLE
THE TOP-DOWN
APPROACH
There are at least two major problems scientists have been facing for
decades that have impeded their efforts to create robots: pattern recognition and common sense. Robots can see much better than we can,
but they don't understand what they see. Robots can also hear much
better than we can, but they don't understand what they hear.
To attack these twin problems, researchers have tried to use the
"top-down approach" to artificial intelligence (sometimes called the
"formalist" school or GOFAI, for "good old-fashioned AI"). Their goal,
roughly speaking, has been to program all the rules of pattern recognition and common sense on a single CD. By inserting this CD into a
computer, they believe, the computer would suddenly become selfaware and attain humanlike intelligence. In the 1950s and 1960s great
progress was made in this direction, with the creation of robots that
could play checkers and chess, do algebra, pick up blocks, and so forth.
Progress was so spectacular that predictions were made that in a few
years robots would surpass humans in intelligence.
At the Stanford Research Institute in 1969, for example, the robot
SHAREY created a media sensation. SHAREY was a small PDP computer placed above a set of wheels with a camera on top. The camera
was able to survey a room, and the computer would analyze and identify the objects in that room and try to navigate around them. SHAREY
was the first mechanical automaton that could navigate in the "real
world," prompting journalists to speculate about when robots would
leave humans in the dust.
But the shortcomings of such robots soon became obvious. The
top-down approach to artificial intelligence resulted in huge, clumsy
robots that took hours to navigate across a special room that contained
only objects with straight lines, that is, squares and triangles. If you
placed irregularly shaped furniture in the room the robot would be
powerless to recognize it. (Ironically, a fruit fly, with a brain containing only about 250,000 neurons and a fraction of the computing power
of these robots, can effortlessly navigate in three dimensions, execut-