DESIGNS THAT FIT - Human-Computer Interaction and Management Information Systems: Foundations - page 190

Figure 10.1 Framework for Understanding Fit in HCI

User
{Physical, Cognitive}

Performance

FIT

Well-Being

Task Computer

note that within the left-hand box of Figure 10.1, the label “fit” is located in between the three fac-
tors: the user, the task, and the computer. In the right-hand box are two impacts of fit: the user's
task-related performance and the user's overall well-being. Task-related performance has to do
with the quality of the task output and the amount of resources consumed, e.g., the accuracy of the
task and the effort and speed needed to complete the task. Overall well-being is the user's physi-
cal, psychological, and social state impacted by the human-computer interaction, e.g., health haz-
ards, emotions, and interpersonal relations. The general thrust of fit models is that fit enhances
one or both results. Using this framework, I first review extant conceptualizations of fit in HCI
and then examine what further aspects of fit should be studied.

EXAMPLES OF FIT IN HCI DESIGN

This section begins with a general call for “designs that fit human capabilities,” continues with phy-
sical fit, and then concentrates on cognitive fit. The next section adds affective fit and proposes
a more general view with some possible extensions.

Design to Fit Users' Capabilities

Baecker et al. (1995) claim that “With a 'good' interface, human and computer should augment
each other to produce a system that is greater than the sum of its parts” (p. 667). This claim
assumes that the computer is designed in such a way that both the computer and the user perform
the tasks that best suit their respective capabilities. The authors go on to emphasize that “a 'good'
interaction technique maximizes human strengths, while a 'poor' one exposes [human] limita-
tions” (p. 668). Following this line of thought, one can see why it is important to design for human
error (an example of adapting the computer to user characteristics) and why it is important to train
users (an example of adapting the user's knowledge to attributes of the computer). In general, the
field of HCI has stressed designing far more than training.
This view follows the systems perspective in proposing a design principle that strives to best
fit the computer functionality to the user's capabilities. Such designs enable an efficient allocation
of tasks to human and computer that is based on an understanding of the characteristics of both
the user and the computer and of their relative strengths and weaknesses. Although the examples
given are taken from the cognitive world, the same logic can be extended to the physiological
aspects of the user and perhaps to the affective aspects, too. For example, our motor capabilities
make it difficult to drag a figure on a computer screen so that it exactly aligns with another figure.