Information Technology Reference
In-Depth Information
motion studies” conducted by Frank and Lilian Gabreth in the 1920s. In
fact, there is evidence that the closely related fi eld of ergonomics was a
design concern even in ancient Greece (see Marmaras et al. 1999). Human
factors and ergonomics are concerned with taking the human's physical
and cognitive abilities into account in the design of things humans use, as
the sidebar illustrates with the evolution of the automobile “interface.” An
important characteristic of the human factors world before computerization
was that the elements of the “interface”—the chair or airplane—were fi xed
in space and existed with fi xed operational characteristics. The plasticity of
the human-computer interface created huge new problems and opportuni-
ties for the human factors fi eld. The “interface” was a powerful bridge, and
design began to rely more upon cognitive aids such as metaphors rather
than upon the characteristics of the body
per se
.
“Interface” became a trendy (and lucrative) concept in the 1980s and
1990s—a phenomenon that is largely attributable to the introduction of the
Apple Macintosh. Interface design was concerned with making computer
systems and applications easy to use (or at least usable) by humans. When
we thought of human-computer interfaces in those days, we were likely to
visualize icons and menu bars or perhaps command lines and blinking cur-
sors. But, of course, many conceptions came before as well as after.
John Walker (founder and president of Autodesk, Inc.) provides an il-
luminating account of the “generations” of user interface design (Walker
1990). In the beginning, says Walker, there was a one-on-one relationship
between a person and a computer through the knobs and dials on the front
of massive early machines like the ENIAC. The advent of punched cards
and batch processing replaced this direct human-computer interaction with
a transaction mediated by a computer operator. Time-sharing and the use
of “glass teletypes” reintroduced direct human-computer interaction and
led to the command-line and menu-oriented interfaces with which the se-
nior citizens of computing (people over forty) are probably familiar. Walker
attributes the notion of “conversationality” in human-computer interfaces
to this kind of interaction, in which a person does something and a com-
puter responds—a tit-for-tat interaction.
This simplistic notion of conversation led many early interface special-
ists to develop a model of interaction that treats human and computer as
two distinct parties whose “conversation” is mediated by the screen. But as
advances in linguistics demonstrated, there is more to conversation than tit
for tat. Dialogue is not just linearized turn-taking in which I say something,
you go think about it, then you say something, I go think about it, and so
