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From: WYLAND@SRI-KL.ARPA
Newsgroups: net.ai
Subject: Stolfo's call for discussion
Message-ID: <12526@sri-arpa.UUCP>
Date: Wed, 18-Apr-84 07:22:44 EDT
Article-I.D.: sri-arpa.12526
Posted: Wed Apr 18 07:22:44 1984
Date-Received: Fri, 11-May-84 08:18:38 EDT
Lines: 63


        Your question - "What are the fundamental characteristics
of AI computation that distinguish it from more conventional
computation." - is a good one.  It is answered, consciously or
unconsciously, by each of us as we organize our understanding of
the field.  My own answer is as follows:

        The fundamental difference between conventional programs
and AI programs is that conventional programs are static in
concept and AI programs are adaptaive in concept.  Conventional
programs, once installed, have fixed functions: they do not
change with time.  AI programs are adaptive: their functions and
performance improve with time.

        A conventional program - such as a payroll program, word
processor, etc. - is conceived of as a static machine with a
fixed set of functions, like a washing machine.  A payroll
program is a kind of "cam" that converts the computer into a
specific accounting machine.  The punched cards containing the
week's payroll data are fed into one side of the machine, and
checks and reports come out the other side, week after week.  In
this concept, the program is designed in the same manner as any
other machine: it is specified, designed, built, tested, and
installed.  Periodic engineering changes may be made, but in the
same manner as any other machine: primarily to correct problems.

        AI programs are adaptive: the program is not a machine
with a fixed set of functions, but an adaptive system that grows
in performance and functionality.  This focus of AI can be seen
by examining the topics covered in a typical AI text, such as
"Artificial Intellegence" by Elaine Rich, McGraw-Hill, 1983.
The topics include:

  o  Problem solving: programs that solve problems.
  o  Game playing
  o  Knowledge representation and manipulation
  o  Natural language understanding
  o  Perception
  o  Learning

        These topics are concerned with adaptation, learning, or
any of several names for the same general concept.  This seems to
be the consistant characteristic of AI programs.  The interesting
AI program is one that can improves its performance - at solving
problems, playing games, absorbing and responding to questions
about knowledge, etc. - or one that addresses issues associated
with problem solving, learning, etc.

        The adaptive aspect of AI programs implies some
difference in methods used in the programs.  AI programs are
designed for change, both by themselves while running, and by the
original programmer.  As the program runs, knowledge structures
may expand and change in a number of dimensions, and the
algorithms that manipulate them may also expand - and change
THEIR structures.  The program must be designed to accommodate
this change.  This is one of the reasons that LISP is popular in
AI work: EVERYTHING is dynamically allocated and modifyable -
data structures, data types, algorithms, etc.

        Good luck in your endeavors!  It is a great field!

Dave Wyland
WYLAND@SRI