ance to a particular function or
digital data. I have illustrated
this here through the example
of the thematic backgrounds.
As I write this, the two prototypes
are still being used in the real
world. We are currently planning
a follow-up study with a total set
of 10 prototypes. I find this very
promising, not merely because it
makes me feel good about my work,
but more so because I see it as a
sign that society and industry are
getting more and more ready for
a tangible interaction paradigm.
One subject I still want to address,
though, is doing longitudinal stud-
ies with tangible interfaces, as
it presents the consequences of
tangibility in a more critical light
(both for industry as well as for
academic research). Looking at my
five iterations, the major differ-
ence between the last one and the
first lies in the duration of the test-
ing period and the consequential
quality of the prototype. To put it
bluntly, the earlier prototypes were
tested for a few weeks at the most,
which determined the maximum
period they had to maintain their
quality. This is pure pragmatism:
There is a trade-off between the
necessary quality of a prototype
and the consequential time invest-
ment. The final prototypes, on the
other hand, were to endure for a
year of intensive day-to-day testing.
As a result, I had to solve quite a
few prototyping issues to guarantee
durability and safety. For example,
whereas the earlier prototypes often
needed instant fixes between test
sessions, I could not afford driving
between test locations scattered
over the country every time some
animal lost its head—literally. This
forced me to completely rethink
my prototype production method.
An impactful issue here was the
prototype’s scale. The final prototype saw an explosion in its vastness compared to the earlier ones.
Moreover, it had to be manufactured
in threefold by myself, which meant
lots and lots of work. And although
I am not afraid to get my hands
dirty, it does illustrate that there is
a consequence to doing longitudinal
research with tangible interfaces.
Ultimately, I spent eight months
designing, animating, voice-overing,
programming, and prototyping to
get to a sufficient level of quality
for a 10-month testing period.
The important question is, of
course: Was the amount of work
worth it? I am convinced it was.
First of all, for my research it was
essential that LinguaBytes could be
adjusted to the developmental level
of individual children, while taking
their personal needs, skills, and preferences into account. This required
a broad range of learning materials.
Second, as the only way to draw
conclusions about LinguaBytes’ language stimulation properties was to
longitudinally test it, large quantities (and very durable) hardware
and software were needed. Third,
to properly determine LinguaBytes’
required adaptability and adaptiv-ity [ 4] it was necessary to get insight
into the complete system. To achieve
this, I felt it necessary as
a researcher to leave as little as
possible to the imagination; doing
research in complex real-world contexts simply requires detailed design
prototypes that allow for diversity,
subtlety, and richness during their
confrontation with the world. Only
when we take the whole human
seriously in interaction design can
we make it truly meaningful.
1. Hengeveld, B. Designing LinguaBytes: A tangible
language learning system for non- or hardly speaking toddlers. Doctoral Dissertation, Eindhoven
University of Technology, 2011.
2. Shaer, O. and Hornecker, E. Tangible user
interfaces: Past, present, and future directions.
Foundations and Trends in Human–Computer
Interaction 3, 1–2 (2009), 1–137.
3. Fernaeus, Y., Tholander, J., and Jonsson, M.
Beyond representations: Towards an action-centric
perspective on tangible interaction. International
Journal of Arts and Technology 1, 3/4 (2008), 249–267.
4. Hengeveld, B., Hummels, C., Overbeeke, C. J., van
Balkom, H., Voort, R., and de Moor, J. Adapt or be
adapted. Proc. of Physicality 2007 (Lancaster, UK). 27–32.
ABOUT THE AUTHOR
Bart Hengeveld is an associate
professor in the Designing Quality
in Interaction group at TU
Eindhoven. He has a master’s
degree in industrial design engi-
neering from TU Delft. In 2006 he
started his doctoral research, LinguaBytes, at TU
Delft, transferring to TU Eindhoven in 2007, where
he defended his research in 2011.
© 2013 ACM 1072-5520/13/11 $15.00
• The final
figures that were
made by hand, in
threefold for the