p.95"Thus, 'heuristic programming' refers to computer programs that
employ procedures not necessarily proved to be correct, but which seem to be plausible. Most problems that have been considered
by AI researchers are of the sort where no one knows any practical, completely correct procedures to solve them; therefore,
a certain amount of proficiency in using hunches and partially verified search procedures is necessary to design programs
that can solve them. So, by a heuristic is meant some rule of thumb that usually reduces the work required to solve
a problem. (Again, it may be possible to prove that the heuristic will always supply solutions to some set of problems,
i.e., that it is algorithmic.) Clearly, much of the conscious thinking that people do is based upon the use of heuristics
that have not been shown to be algorithms. The realization of this fact and its incorporation in the design of computer programs
was an important step in the development of artificial intelligence, signifying a recognition by AI researchers that intelligence
is often exhibited in situations where one's understanding and knowledge are incomplete."
Why is it important to calculate the "favorableness" of positions
in a game tree accurately? According to Jackson, the alpha-beta search procedure becomes more efficient if the moves searched
are ordered correctly:
p.134"However, the worth of the technique [alpha beta tree search]
is greatly dependent upon the order in which the nodes of the tree are taken for examination... In using the alpha-beta technique,
it is desirable to have some method that will make it likely the best nodes are evaluated first."
