[net.ai] Seminar - Learning About Systems That Contain State Variables

Hamilton.ES@XEROX.ARPA (04/24/84)

From:  Bruce Hamilton <Hamilton.ES@XEROX.ARPA>

The research described below sounds closer to what I had in mind when I
raised this issue a couple of weeks ago, as opposed to the
automata-theoretic responses I tended to get.  --Bruce

[For more leads on learning "systems containing state variables", readers
should look into that branch of control theory known as system identification.
Be prepared to deal with some hairy mathematical notation.  -- KIL]


  Date: 24 Apr 84 11:39 PST
  From: mittal.pa
  Subject: Reminder: CSDG Today

  The CSDG today will be given by Tom Dietterich, Stanford University,
  based on his thesis research work.
  Time etc: Tuesday, Apr. 24, 4pm, Twin Conf. Rm (1500)

Learning About Systems That Contain State Variables

It is difficult to learn about systems that contain state variables when
those variables are not directly observable.  This talk will present an
analysis of this learning problem and describe a method, called the
ITERATIVE EXTENSION METHOD, for solving it.  In the iterative extension
method, the learner gradually constructs a partial theory of the
state-containing system.  At each stage, the learner applies this
partial theory to interpret the I/O behavior of the system and obtain
additional constraints on the structure and values of its state
variables.  These constraints trigger heuristics that hypothesize
additional internal state variables.   The improved theory can then be
applied to interpret more complex I/O behavior.  This process continues
until a theory of the entire system is obtained.  Several conditions
sufficient to guarantee the success of the method will be presented.
The method is being implemented and applied to the problem of learning
UNIX file system commands by observing a tutorial interaction with UNIX.