From: rusty@groan.Berkeley.EDU (Rusty Wright)
Newsgroups: rec.games.mud.misc
Subject: interesting reading part 2
Date: 23 Jan 93 00:00:19 GMT
Organization: University of California Berkeley
NNTP-Posting-Host: groan.berkeley.edu

Here is some possibly interesting reading from a back issue of ART
COM.  I've exceprted the relevant articles.

ART COM (electronic) Magazine #43 and #44 (Nov & Dec '90) were devoted to
Interactive Fiction.  These two back issues are available by e-mail.  Send
requests to dag@hpsemc.cup.hp.com, with the one-word Subject: ArtCom.
Requests are processed by a program; append a personal message if you wish.

  /\    ___  ___   ___  ___  __  __
 /__\  /__/  /    /    /  / /  /  /
/    \/   \ /    /__  /__/ /  /  /
-----------------------------------------------------------------
DECEMBER 1990           NUMBER  44          VOLUME 10   NUMBER 10
-----------------------------------------------------------------

Welcome to ART COM, an online magazine forum dedicated to the 
interface of contemporary art and new communication technologies. 

You are invited to send information for possible inclusion. We are 
especially interested in options that can be acted upon: including 
conferences, exhibitions, and publications. Proposals for guest 
edited issues are also encouraged. Send submissions to: 
 
                    well!artcomtv@uunet.uu.net
                    artcomtv@well.sf.ca.us

Back issues of ART COM can be accessed on the Art Com Electronic 
Network (ACEN) on the Whole Earth 'Lectronic Link (WELL), 
available through the CompuServe Packet Network and PC Pursuit. 

To access the Art Com Electronic Network on the WELL, 
enter  g acen  at the Ok: prompt. The Art Com Electronic 
Network is also accessible on USENET as alt.artcom.
For access information, send email to: artcomtv@well.sf.ca.us. 

*Guest Editor: Abbe Don
*Executive Editor: Carl Eugene Loeffler
*Editor: Anna Couey
*Systems: Fred Truck and Gil MinaMora

ART COM projects include:

ART COM MAGAZINE,  an electronic forum dedicated to contemporary art 
and new communication technologies.

ART COM ELECTRONIC NETWORK (ACEN), an electronic network dedicated to 
contemporary art, featuring publications, online art galleries, art 
information database, and bulletin boards.

ART COM SOFTWARE, international distributors of interactive video and 
computer art.

ART COM TELEVISION, international distributors of innovative video to 
broadcast television and cultural presenters.

CONTEMPORARY ARTS PRESS, publishers and distributors of books on 
contemporary art, specializing in postmodernism, video, computer 
and performance art.
 
ART COM,  P.O. Box 193123 Rincon Center, San Francisco, CA, 94119-3123, USA.
WELL E-MAIL: artcomtv TEL: 415.431.7524  FAX: 415.431.7841

-------------- A R T  C O M / DECEMBER 1990 / VOL. 10(10) / #44 --------------

                 LIFE-LIKE CHARACTERS IN INTERACTIVE FICTION

                                 David Graves

David Graves (dag@hpsemc.cup.hp.com) has been doing research and
development in Interactive Fiction for the last six years.  He is
currently collaborating with writers on several IF projects, using a
software platform of his own.


A common failing of interactive fiction today is that the player is
totally responsible for the progress of the plot.  Whenever the player
cannot solve a given puzzle, progress grinds to a halt.  Most
interactive fiction works are entrenched in this obstructionist model.
There is no plot continuity, and too little dramatic interaction.  Our
characters are not pulling their own weight.

The first step is to take the player out of the role of being
responsible for the flow of the plot.  In her PhD dissertation, Brenda
Laurel explains: "The user of an interactive system may indeed make
contributions on the level of plot; however, the responsibility for
integrating such contributions into the whole and creating other plot
elements that maintain the necessary dramatic qualities in the whole
belongs to the system.  When that responsibility devolves to the user,
first-personness is destroyed, as in the classroom improvisation where
the actor must divide his attention between acting and playwriting
tasks.  By assuming formal control of the action, the system frees the
user from playwriting concerns and allows him to immerse himself in
the experience of his character."

Furthermore, the characters found in most computer games are cardboard
cutouts, without any personality.  In her PhD dissertation, Mary Ann
Buckles points out this failing in the original Adventure game, which
still applies to most games today: "The characters the reader
encounters in the fictional underworld have no significance other than
to pose a puzzle for the reader.  The reader has little emotional
involvement with the characters because they, in turn, do not
represent any emotional or spiritual facets of human existence."
Artificial Personality addresses this need for simulating personality
in our characters.

Almost all attempts to generate behavior in computer-controlled
characters have followed a simple stimulus/response model.  For each
statement you may make to character, there is one response it may
display.  Giving the same stimulus several times in a row, the
character will mindlessly repeat the same response.  Clearly, there is
room for improvement in creating lifelike characters, but how can we
attack such a difficult task?  To start, we can borrow a number of
ideas and methods from the field of Artificial Intelligence, avoiding
the difficult software problems, to produce the >illusion< of
intelligent, emotional, motivated characters.

In order for characters to act intelligently they must be able to
interpret the state of their environment and apply appropriate
behaviors.  While applying a problem solving procedure to achieve some
goal, however, complications may arise.  In traditional interactive
fiction, we pass all these problems to the player.  Instead of
troubling the player character with minor complications, the game
software could automatically resolve them.  For example, given the
command "Drink the beer," rather than having a character complain "The
beer isn't open," it could recognize "Open the beer" as an implied
subgoal.  Any given goal could give rise to a number of subgoals,
which may create subgoals of their own.  When a character is able to
handle low level logistics without being given explicit instructions,
he appears much more intelligent.  This technique also provides a
mechanism for handling tedious logistical details on behalf of the
player, who is then free to think at higher levels.

No organism's behavior is ever unmotivated.  Thus, in order for
characters to display behaviors that appear reasonable and believable,
they must have their own motivations.  These motivations help
stimulate the generation of plot.  However, without guidance for the
plot, chaos is a likely result.  To ensure that the generated plot is
interesting, the system could have some concept of drama and apply it
to the currently unfolding story.  Laurel's dissertation gives an
outline of an expert system to do just that.  "Understanding a story
in its totality is a task that integrates natural language
understanding and the understanding of characters' goals, plans,
traits, and emotions, and utilizes still other techniques for
identifying larger patterns of action."  This computerized playwright
would recognize opportunities for new plot twists and act on them.
Clearly, this is a lofty vision, requiring vast resources to
implement.

Several projects have been successful in creating small expert systems
that focus on character behavior and interaction, rather than
attempting to recognize and generate plot units.  This requires a
representation (in software) for the emotional state and goals of each
fictional character.  Using this model, each character's emotional
state and current goals drive the selection of a specific behavior
from a large set of possible behaviors.  The intensity of the
appropriate emotion values is then used to determine the intensity of
the expression of the behavior.  Even when performing simple actions,
a character's hidden emotional state may "leak out."  Thus, the way in
which a character attempts to accomplish his goals may be influenced
by his emotions and those of the other characters.  Due to the
complexity of the emotional state of the characters, the sub-plot
twists are unpredictable, and due to the goals inserted at
plot-critical times, the author can control the overall plot coherence
and pace.

In creating a model of personality and relationships, one must select
a manageable set of emotion variables.  The magnitude of these
variables will define how each character relates to the others.  Each
of these emotion values tells how one character feels about another.
John may love Mary, but Mary may not love John.  Conflicting emotions
and goals between characters help keep the action lively, giving rise
to new goals all the time.  In addition to these two dimensional
emotions (directed towards other characters), some one dimensional
emotion variables may be created, which indicate a character's
internal emotional state or mood, or personality attributes that
remain constant.  Michael Lebowitz, creator of a program that writes
soap opera stories, uses one-dimensional attributes such as niceness,
guile, physical appearance, and promiscuity.

In most interactive fiction products, characters are treated as
objects.  Most interactions with other characters are limited to
making imperative statements to them (giving commands).  True
interaction with characters is impossible in these worlds because the
representation of the world is void of any "interactive media."  You
cannot talk with them because there is nothing to talk about.  In
worlds containing only objects, the only topic of discourse is the
"object economy" (physical objects that may be manipulated).  In order
to produce interaction on more human terms, a system must have (1) a
rich representation for emotions, knowledge, and beliefs, (2) a rich
set of behaviors that are driven by those items, and (3) a rich
grammar for communication of knowledge, events, beliefs, and emotions.
These subsystems must be fully integrated with each other.  One would
not want to design-in emotions that cannot influence behavior, or that
cannot be talked about using the input grammar.

At the center of any Artificial Personality system is an emulation of
human emotions.  Besides providing new motivation for believable
behavior, emotions give the characters a new domain for discourse.
They may interact on the levels of physical state, information state,
and emotional state.  In designing an interactive story, the designer
must keep in mind the interlocking dimensions of physical state,
emotions, character beliefs, behavior, and communication.  One must
also keep sight of the vision: characters displaying believable
original behavior and engaging in interesting, dramatic interaction.

NOTES

Brenda Laurel: "Towards the Design of a Computer-based Interactive
Fantasy System" (1986).  Defines the vision and the technologies
required to implement it.

Mary Ann Buckles, "Interactive Fiction: The Computer Storygame
'Adventure'" (1985).

Michael Lebowitz, "Creating Characters in a Story-Telling Universe"
Poetics, 13, 171-194. (1984)
Xref: sparky rec.games.mud.misc:2071 rec.games.mud.lp:5005