Automotive User Interfaces and Interactive Vehicular Applications

Open Car User Experience Lab:
A Practical Approach to Evaluating Car HMIs Holistically
David Wilfinger, Martin Murer, Manfred Tscheligi
Christian Doppler Laboratory for Contextual Interfaces, ICT&S Center, University of Salzburg
Sigmund Haffner Gasse 18
5020 Salzburg, Austria
[david.wilfinger, martin.murer, manfred.tschelig]@sbg.ac.at
ABSTRACT
Multifunctional human machine interfaces have pervaded
modern cars in the last decade. Following user centered
design traditions, these interactive systems need to be evaluated
in all stages of development. This requires evaluation
approaches, which take the multiple facets of these systems
in a dynamic context into account. This work presents the
“Open Car User Experience Lab” approach for evaluating
modern in-car HMIs by combining expert and user based
evaluation methods. The poster introduces the system aspects,
which have to be investigated, the methods to do
so and finally describes an example study in which the approach
is used.
Keywords
Automotive User Interface, Evaluation, User Experience
1. INTRODUCTION
A positive trend in automotive HMI (human machine interfaces)
is the ongoing development of systems, which combine
tertiary car functionality in a central location. As in all areas
of human machine interaction, those interfaces undergo
a constant stream of development, deployment and redesign
for a next car generation. Most studies in the development
of in car HMIs are studies in a laboratory. We nevertheless
argue that field studies are necessary to raise the level of
realism and to take the influence of the usage context into
account. This poster contributes to HMI development by
showing a way to evaluate state-of-the-art in car interfaces
from a user centered perspective, using a reasonable amount
of resources while still gaining sufficient information for a
design iteration of these systems. Therefore, we introduce
the so-called Open Car UX Lab approach, being a compromise
between a controlled laboratory experiment and a long
term field study. The name also indicates the independency
of the approach from car manufacturers, allowing a neutral
evaluation of multifunctional HMIs in the car.
Copyright held by author(s)
AutomotiveUI’11, November 29-December 2, 2011, Salzburg, Austria
Adjunct Proceedings
- 37 -
2. APPROACH
In current HCI research, expert and user based evaluation
approaches are often seen as being alternating, with an expert
evaluation in the early stage and a user based study
with the system in a later stage of development. We nevertheless
argue that both expert and user based approaches
can be used beside each other, especially when an in-car interface
is supposed to be evaluated holistically, i.e. taking
aspects of system, user and context into account. Therefore
we decided to combine both expert and user based approaches
and match them to research foci, which are expected
to be suited for either one of the approaches. Experts
mainly investigate basic ergonomic aspects of the system,
which can be rated using guidelines or which can not be investigated
with users in a reasonable amount of time during
a task based evaluation. The user focus, on the other hand,
lays on distraction, effectiveness, efficiency and user experience.
Especially, the experience related measures have to be
conducted together with users and are very hard to be evaluated
by experts, whose potential to empathize with users
is limited.
In order to evaluate a system it is necessary to define, which
aspects of the system are under investigation. For that purpose,
we gathered a group of automotive HMI experts (with
backgrounds in psychology, computer science and design),
who developed a list of foci, based on a review of related
literature (in random order):
A Accessibility / Ergonomics of input elements. This
refers to how well interactive elements can be accessed according
to aspects of ergonomics.
B Readability of displays and labels. Describes how
well interactive elements can be perceived by users.
C System logic, connection of software and hardware
elements. This focuses on the internal consistency
and other aspects of a menu design, which influence the human
machine interaction.
D Usability (efficiency and effectiveness). Effectiveness
refers to the successful completion of a task and the
quality of the system in supporting the user to do so. Efficiency
describes how much resources have to be invested
in order to complete a task, in the case of our approach it
refers to the time needed to complete a task.
E Distraction caused by the system usage. In automotive
HMI, distraction caused by a system is often seen as
time spent not looking at the road but at a certain interface
element.