SatNav or SatNag? - Human-Computer Interaction and Innovation in Handheld, Mobile and Wearable Technologies - page 316

CASE STUDY ANALYSIS largely build upon previous solutions and

the lessons learned in feedback activities.
• Tension 3: The complexity of issues in-
volved in designing a car requires a di-
verse range of professionals to collabo-
rate on important design decisions (e.g.
where a touchscreen should be located in
a vehicle). Such people may have a strong
human-centred view (e.g. HCI/Human
Factors practitioners), but may well be
driven by other competing perspectives
(e.g. stylists, engineers, marketing, and so
on). Consequently, design decisions for
vehicles must typically be supported by
'hard' data, often quantifiable and based
on research with strong 'believability' (or
face validity). Such data particularly as-
sists HCI practitioners to argue a case to
the wide range of stakeholders involved in
the design process who may have compet-
ing viewpoints.
• Tension 4: A final difficulty occurs be-
cause of the need for fixing (or freezing)
aspects of vehicle design early in the de-
sign process, particularly relating to hard-
ware decisions (e.g. the number of buttons
on a panel). This creates a conflict with the
HCI philosophy of a continuing cycle of
iterative design and evaluation.

The remainder of this paper will focus on the
evolving HCI issues for a specific case study
system, that is, vehicle navigation. This is an in-
car computing technology with which I have been
involved in a large number of research studies
in the last 15 years, commencing with my own
PhD work (Burnett, 1998). Relationships with the
four tensions described above and the concepts of
overload and underload will be described, where
appropriate.
Navigation systems within vehicles aim to sup-
port drivers in the strategic and tactical components
(planning and following routes respectively) of the
driving and navigating task. They have become
increasingly popular in recent years, across many
countries, as costs have reduced and the technol-
ogy has matured.
There is a considerable literature focusing on
human-centred design issues for vehicle naviga-
tion systems. As such, this technology serves as
an interesting case study in the consideration of
HCI issues for in-vehicle computing. Much of
the work in the area has emerged from the Hu-
man Factors/Ergonomics discipline. Indeed, from
around 1985 until approximately 2000, the only
research papers that can be found on the topic are
within Human Factors/Ergonomics journals and
conferences. Nevertheless, more recently there
have been several prominent papers within the
core HCI literature (e.g. Sodnik et al., 2008; Lee,
Hoffman and Hayes, 2004). It is not the purpose
of this paper to ignite any controversy concern-
ing the scope of Human Factors/ Ergonomics and
HCI and their inter-relationships. Suffice to say,
this is a design space in which researchers and
practitioners from both domains have a critical
role to play in the development of systems which
are both usable and safe to use.
It is evident that the great majority of research
in this area has made very convincing safety argu-
ments, assuming that overload is the most likely
concern that navigation system designers must

As noted by myself (Burnett, 2008) and others
(see, for example, Walker, Stanton and Young,
2001), the key HCI design issues for in-car com-
puting systems orientate around two diverse needs.
For certain systems (e.g. those providing email
access), there is a fundamental desire to avoid
driver overload (divided attention, high levels
of mental workload and stress, etc.). Conversely,
for other systems (e.g. adaptive cruise control)
research aims to minimise the likelihood or con-
sequences of underload due to the automation of
core driving tasks (reduced situation awareness,
negative behavioural adaptation, de-skilling, etc.).