Dramatic Foundations - Computers as Theatre - page 56

Given these defi nitions, we can now take a run at the four causes as ap-
plied to human-computer interaction:
Formal cause: The formal cause of a particular human-computer activ-
ity (that is, an extended set of interactions bound together) is the form
of what it's trying to be. Human-computer interaction generally lacks
the kind of well-known formal categories that drama offers (comedy,
tragedy, etc.), although game genres like “fi rst-person shooter” or tools
like a “video editor” have formal characteristics. 6 What we can say,
however, is that the form of human-computer activity is a representa-
tion of action with agents that may be either human, computer-based,
or a combination of both. We will discover more of the characteristics
of that form as we identify its structural elements and the relations
among them.
Material cause: The material cause of a human-computer interaction,
like a play, is the enactment—that which unfolds before a person's
senses. As plays employ the sights and sounds produced by actors
moving about in scenic environments, computers may employ anima-
tion, sound and music, text characters, or tactile and kinesthetic effects
(e.g., force feedback). In the discussion of structural elements ahead,
we will see how these sensory materials are shaped into more sophisti-
cated constructs.
Effi cient cause: The effi cient cause of human-computer interaction is
the skills and tools of its maker(s). Since a given application is prob-
ably based, at least in part, on chunks of program code that have been
created by other people for other purposes, the computer equivalent
of a playwright is usually a group of people. Both theatre and human-
computer activity design are collaborative disciplines; both depend
upon a variety of artistic and technical contributions. Some of those
contributions may have already been produced, as in code libraries or
scenery, whose makers may never be met by the production team, but
who are nonetheless time-displaced collaborators. In both domains, the
6. Although application categories like “document creation” or “productivity” are sometimes
invoked by designers as if they were formal criteria, I would argue that they are rather part
of the end cause, since their defi nitions are essentially functional rather than formal. As most
computer-using writers know, it is still impossible to derive the “canonical” form of a word
processor from all of the instances that exist on the market; we can only speak about a word
processor's expected or necessary functionality.