Information Technology Reference
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Letting the user indicate a general direction and location and leaving the exact alignment to the
computer demonstrates the design principle of fitting the computer to the user's capabilities.
Whether based on cognitive or motor capabilities, the strategy of achieving fit with user charac-
teristics appears to be acknowledged by some leading HCI researchers as a useful guideline for
practice. This may be considered as the most basic and general call for fit in designing HCI. I now
turn to more specific treatments of fit in design.
Physical Fit
Although the term physical fit is not used widely, the connotation of matching the physical
designs of input and output devices to the physiology of the user is at the heart of ergonomic
design. For example, the popular flat keyboard is designed to fit the shape and size of the hands.
Improved ergonomic designs that better fit the shape of the hand provide a tilted and curved key-
board that reduces the carpal tunnel stress that can result from lengthy typing sessions. Yet, over-
all, the fit of most input and output devices to the physiology of our entire body is rather limited,
as evident in an amusing but very telling scenario introduced by Buxton (1986).
Imagine a futuristic situation in which all knowledge about our civilization has been lost and
the only clues available were to be found in a computer equipment store that, by some unexplained
miracle, had been preserved intact with all its equipment fully operable. A physical anthropolo-
gist was summoned to simulate the physiology of the (presumably) humans who used this equip-
ment. What would they look like? One likely picture of a human would be of a creature “with a
well-developed eye, a long right arm, a smaller left arm, uniform-length fingers and a 'low-fi' ear.
But the dominating characteristics would be the prevalence of our visual system over our poorly
developed manual dexterity” (Buxton, 1986). There would be hardly any clues in the computer
store about our other senses, nor about our “other” eye and ear, not to mention our legs and feet.
The difference between this human being and the one we know is amazing and, more importantly
for designers of HCI, perplexing. In fact, had the physical anthropologist explored a driver's seat
in a regular car, a more balanced view of our physiology would probably emerge.
Fortunately, new and improved ergonomic designs have emerged in the past twenty years (e.g.,
handheld devices and the click wheels on Apple's iPods). Nevertheless, Buxton's scenario is insight-
ful. It highlights the extent to which the most popular input-output devices many people use on a
daily basis (and some use them most of the day) are very poorly matched to our body. Using only a
fraction of our faculties, current technology strains those it uses, and is so poorly fitted to our phys-
iology that it often causes poor performance, frustration, fatigue, and long-term health hazards.
Ergonomic design of input and output devices concentrates on fitting the device to human
physiology in performing generic, rather than specific, tasks, such as inputting numeric data to a
computer or reading text from a computer screen. The general assumption is that good fit should
require less effort, reduce health problems, and generate in the user a positive sensation or feeling
of physical comfort. On the other hand, poor fit will usually require more muscular effort, result
in physical strain during or after the activity, and generate uncertainty about the physical interac-
tion with the computer.
Although anecdotal evidence suggests that health problems due to inadequate designs and
poor work habits with computers cause significant damage to organizations, there is a paucity of
research in the IS literature about the consequences of poor fit on performance and well-being.
Indeed, the practical applications of fitting hardware to attributes of human physiology have
stressed the impact on health and well-being, and only indirectly on performance, e.g., loss of
working hours due to health problems (e.g., Sandsjo et al., 2003).
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