With these lessons firmly in mind, Farmer together with five other
physicists (one of them a former Chaos Cabal member) engineered a
start-up company to crack every gambler's dream: Wall Street. They would
use high-powered computers. They would stuff them with experimental
nonlinear dynamics and other esoteric rocket-scientist tricks. They
would think laterally and let the technology do as much as possible
without their control. They would create a thing, an organism if you
will, that would on its own gamble millions of dollars. They would make
it...(drum roll, please)... predict the future. With a bit of bravado,
the old gang hung out their new shingle: the Prediction Company.
The guys in the Prediction
Company figure that looking ahead a few days into the financial market
future is all that is needed to make big bucks. Indeed, recent research
done at the Santa Fe Institute, where Farmer and colleagues hang out,
makes it clear that "seeing further is not seeing better." When immersed
in real world complexity, where few choices are clear cut and every
decision is clouded by incomplete information, evaluating choices too
far ahead becomes counterproductive. Although this conclusion seems
intuitive for humans, it has not been clear why it should pertain to
computers and model worlds. The human brain is easily distracted. But
let's say you have unlimited computing power specifically dedicated to
the task of seeing ahead. Why wouldn't deeper, farther be better?
The short answer is
that tiny errors (caused by limited information) compound into grievous
errors when extended very far into the future. And the cost of dealing
with exponentially increasing numbers of error-tainted possibilities
just isn't worth the immense trouble, even if computation is free (which
it never is). Santa Fe Institute investigators, Yale economist John
Geanakoplos and Minnesota professor Larry Gray, used chess-playing
computer programs as the test-bed for their forecasting work. (The best
computer chess programs, such as the top-ranked Deep Thought, can beat
all human players except for the very best grandmasters.)
Contrary to the expectations of computer scientists, neither Deep
Thought nor human grandmasters need to look very far ahead to play
excellent games. This limited look-ahead is called "positive myopia."
Generally grandmasters survey the chess board and forecast the pieces
only one move ahead. Then they select the most plausible play or two and
investigate its consequences deeper. At every move ahead the number of
choices to consider explodes exponentially, yet great human players will
concentrate only on a few of the most probable countermoves at each
rehearsed turn. Occasionally they search far ahead when they spot
familiar situations they know from experience to be valuable or
dangerous. But in general, grandmasters (and now Deep Thought) work from
rules of thumb. For instance: Favor moves that increase options; shy
from moves that end well but require cutting off choices; work from
strong positions that have many adjoining strong positions. Balance
looking ahead to really paying attention to what's happening now on the
whole board.
Every day we confront similar tradeoffs. We must anticipate what lies
around the corner in business, politics, technology, or life. However,
we never have sufficient information to make a fully informed decision.
We operate in the dark. To compensate we use rules of thumb or rough
guidelines. Chess rules of thumb are actually pretty good rules to live
by. (Notes to my daughters: Favor moves that increase options; shy away
from moves that end well but require cutting off choices; work from
strong positions that have many adjoining strong positions. Balance
looking ahead to really paying attention to what's happening now on the
whole board.)
Common sense embodies a "positive myopia." Rather then spend years
developing a company employee manual that anticipates every situation
that might arise -- yet be out of date the moment it is printed -- how much
better to adopt positive myopia and not look so far ahead. Devise some
general guidelines for the events that seem sure to arise "on the next
move" and treat extreme cases if and when they come up. To navigate
through rush-hour traffic in an unfamiliar city we can either plan
detailed routes through the town on a map -- thinking far ahead -- or adopt a
heuristic such as "Go west until we hit the river road, then turn left."
Usually, we do a bit of both. We refrain from looking too far ahead, but
we do look immediately in front. We meander west, or uphill, or
downtown, while using the map to evaluate the next immediate turn ahead,
wherever we are. We employ limited look-ahead guided by rules of
thumb.
Prediction machinery need not see like a prophet to be of use. It needs
only to detect limited patterns -- almost any pattern -- out of a background
camouflage of randomness and complexity.
continue...
|