DESIGNS THAT FIT - Human-Computer Interaction and Management Information Systems: Foundations - page 198

require nearly continuous adaptations (as in the discussion above on virtual reality). Designers
could also strive to achieve fit dynamically for complex cognitive operations in rich information
environments (e.g., browsing large Web sites through adaptive views). In contrast, achieving affec-
tive fit dynamically has been met with skepticism, primarily because of sensing and measurement
problems. A plausible solution may be adaptable systems in which the system is designed with
the flexibility to let users adapt the system to their emotional state (Tractinsky, 2004).
Perhaps the most common manifestation of fit in practice is personalization. Displaying bright
colors to young users, using French for the French-speaking user and using joyful expressions to
communicate with the happy user are instances of fitting the human-computer interaction to the user
characteristics, that is, personalizing the interface. Moreover, as noted above, human-computer
interaction should be seen as a dynamic process in which designs adapt throughout the dialog.
Indeed, adaptive and adaptable user interfaces are becoming an important area of development. In
adaptable interfaces the user is given the tools to adapt the interfaces to his or her capabilities, level
of knowledge, preferences, or physical setting. In adaptive interfaces the computer initiates the
adaptation. A trivial example is the ability to adapt the brightness of the video terminal to fit the
light in the room. A more complex example is the ability to adapt the content and presentation in a
learning environment to the progress of a student (Papanikolaou et al., 2003).
A framework that integrates the various types of fit and their impact would provide a systematic
basis for personalization. At present, the design of personalization concentrates on isolated aspects
of fit. One interesting example of a more systematic approach is the user-centered approach to per-
sonalization at IBM (Karat et al., 2003). Although, personalization of a Web site connotes a broader
form of adaptation than the HCI focus adopted in this chapter, the basic ideas are very similar. The
researchers produced clusters of adaptable presentation features tailored both to known user char-
acteristics (such as job type) and to the context implied (such as no graphics when response time
is poor). They then sought to determine how personalization would impact effectiveness and ease
of use. Finally, they recommended several policies for personalization, e.g., “adaptive presentation:
The pages displayed are adapted based on my recent navigation path” (ibid., p. 698).
INTEGRATION
This chapter began with several examples of how researchers have conceptualized and advocated
“fit” as a design goal. In particular, I took a critical view and commented on the value, and some-
times deficiencies, of these conceptualizations in contributing to theory and practice. The discus-
sion went on to elaborate some of the concerns that have been voiced and some of the extensions
offered. I now summarize and integrate the discussion by picking up again on some of the points
made above and offering some new directions for studying fit.
Figure 10.2 refines and extends Figure 10.1, summarizing the aspects of fit discussed above. As
already noted, broadening and generalizing some of the extant conceptualization of fit—e.g., from
cognitive fit theory—will be important in enhancing the value of fit in HCI. Our definitions are
accordingly very general. User-computer fit is achieved by matching the computer to the attri-
butes and preferences of the user and is manifested in reduced effort and a better feeling found in
designs of good fit in comparison to designs of poor fit. At the same time, designs should also allow
for user learning and adaptation that achieve fit in ways unforeseen by the designer. One important
element in deciding which direction to take is based on a reality check against the real world of
either the user's mental model or the computer's internal representation.
Fit is multi-dimensional; the dimensions correspond to classes of human attributes. There are
at least three types of fit that the designer needs to consider. Physical fit concerns fit with human