It isn't really. The number of pigeon holes you use to classify plots is
arbitrary. Books have been written asserting that there is only one basic
plot. Others have tried to break plots down into four or seven or a dozen
plots; the most expansive scheme I ever saw had a branching tree structure
which must have had nearly a thousand nodes at its lowest level.
The bottom line here is that no one has ever come up with a good
classification system. The Victorian mania for taxonomy didn't produce
a scheme, and succeeding generations haven't been all that interested
in taxonomy and haven't really tackled the problem. I believe it could
done, but it would take some Casaubon-like neurotic genius a lifetime
to do it. What typically happens is that a) young scholar perceives
need for such a system, b) young scholar devotes several years to
thinking out the two or three most important assumptions of his system,
as a foundation for future work, c) young scholar publishes this as a
prolegomenon; d) young scholar loses interest and abandons further
development of his system, e) next young scholar to come along decides
to develop his own system from scratch, rather than using previous
scholar's work as a platform. Repeat cycle ad nauseam -- this is the
story of Greimas, Pavel and a host of others.
Here is a summary of Polti's system, taken from Brenda Laurel's
TOWARD THE DESIGN OF A COMPUTER-BASED INTERACTIVE FANTASY SYSTEM:
The work of Georges Polti in his book THE THIRTY-SIX DRAMATIC
SITUATIONS is often cited by AI researchers as providing the
basis for an action calculus. Polti asserts that the "thirty-
six situations" reflect the fact that "there are in life but
thirty-six emotions." Although his psychology may be dubious,
Polti's examples are persuasive. He has cited twelve hundred
examples from various literary genres in an attempt to demonstrate
that his "thirty-six situations" are all inclusive. Instead of
plans and goals, Polti employs the following set of primitive
elements (or symbolic units) to create symbolic expressions for
actions: *character types* whose names imply their potential for
action and their key relationships (e.g., The Criminal, The
Jealous Kinsman, The Deceived Husband), *objects or events* (e.g.,
The Mistake, The Coveted Object), and, occasionally, *situational
or motivational elements* (e.g., The Necessity for Sacrifice,
The Cause of the Mistake). Meehan utilizes a similar scheme for
generating stories, but he makes no claim that his "calculus" is
exhautive.
Unfortunately, Polti does not catalog his primitive elements, nor
do they seem to be the product of some systematic categorization
scheme ... Polti's system is reminiscent of the deck of the Tarot
(The Lover, The Queen, etc.) ... elementary plot units are combined
to form larger, recognizable patterns of action....
Polti's book first appeared in 1916. It is a sign of the state of the
art in this field that it is still in print after 73 years.
--
Richard Newsome
Big Electric Cat Public UNIX
..!cmcl2!hombre!dasys1!newsome