Information Technology Reference
In-Depth Information
is either to eliminate one of the activities, or to reshape the action so that
it includes both in a
causally related way
—e.g., a starfi ghter simulation in
which Jimmy solves math problems in order to operate the ship.
6
Besides its function as a criterion for inclusion, playwrights deploy cau-
sality in the shaping of dramatic probability. The representation of certain
causes makes certain effects probable. The possibility of confl ict in the Neu-
tral Zone (part of the dramatic potential of
Star Trek
) becomes a probabil-
ity if a cause is represented—e.g., a Romulan incursion. In complementary
fashion, the representation of effects leads people to expect that causes will
be revealed—another way of constraining what is probable in the action.
A primary source of causality in dramatic incidents is the goals of the
characters, that is, what the characters want and what they are trying to
do (present on the level of Thought). The central action of a play is often
best described in terms of the goal of its central character. The character
tries various courses of action for achieving their goals. The obstacles and
confl icts they encounter force changes in their behaviors and plans, and
sometimes in the goals themselves. A detective character may start out try-
ing to solve a murder and end up embroiled in an international espionage
operation. Of course, by the end of the action, the audience can see that it
was “about” the spy ring all along, because knowing about it makes all the
details fall into place. The central character's goal has carried them along,
and the revelation of the other characters' goals unifi es seemingly unrelated
incidents into a whole action through the interweaving of causality.
7
Likewise, the agents' goals are most often the strongest source of causal-
ity in human-computer activity. What is each agent (human and computer-
based) trying to do, get, or become? What obstacles and confl icts arise, and
how do they constrain what the agents do? In human-computer activity, as
in drama, goals usually lead to the formulation of plans (or strategies) for
achieving them. These plans are either stated or inferred, and they provide
a basis for understanding the action. The implementation, failure, revision,
and formulation of plans are the “meat” of the action. To be probable, goals
and plans must be plausible in terms of the characters that generate them
(the “appropriateness” criterion for character, as discussed in Chapter 2).
6. These three paragraphs are a slightly modifi ed excerpt from “Interface as Mimesis,” in Norman,
D. A. and Draper, S., Eds.,
User Centered System Design: New Perspectives on Human-Computer Inter-
action
. Hillsdale, NJ: Lawrence Erlbaum Associates, 1986. Reprinted with permission.
7. One of the very best examples of the recognition of causality after the action is completed is
the American fi lm
The Sixth Sense
(1999). No spoilers here: If you haven't seen it, watch it!
