children, seniors, and people from
varying cultural backgrounds and
physical ability. In view of this uni-
versal public expectation, we chose
multi-touch surfaces as our primary
interaction methodology at an early
stage of the project. Our ambition
with the user interface design was to
enable intuitive and explorative inter-
action with a virtual representation
while still allowing users to maintain
a mental connection with the corre-
sponding real artifact or subject (see
Figure 6). This has led us to apply de-
sign principles that can be character-
ized by the following parameters:

Object focus. The main focus of the representation on the screen should always be the rendered object, thus placing serious constraints on the choice of interaction paradigms and the implementation;

Judicious interaction constraints and micro-level interaction freedom. Interaction must be perceived as free but still constrained to noninvasively guide the user. We thus chose to constrain global interaction but increase freedom as points of interest are reached;

Minimalistic icons. Icons should be
sparse and blend into the scene so as
not to interfere with the object focus;
they should also be associated with inter-
action points on the touch surface; and
A common technique used in volume
rendering is known as “clipping planes”
to make cutouts and reveal the interior
of an object. From the user perspective,
the planes are depicted as a pair of virtual
scissors that enable virtual dissection of
the subject/object. It is a simple yet pow-
erful technique that is both informative
and visually exciting when the user is
able to discover content inside the skull
or underneath the skin. To minimize us-
age complexity, we limit the interaction
to a few fixed clipping directions with
reduced flexibility. This limited interac-
tion allows the user to explore while still
making sure that focus and context are
not lost due to excessive clipping and an
must be close to zero. In a matter of
a few seconds the user must be able
to grasp how to interact, how to rotate
the objects without losing control,
zoom in and out, and change render-
ing parameters to reveal the data of
interest. During the course of the proj-
ect’s development, touch interfaces
have rapidly become commonplace,
and the potential user base spans
all of modern society. This combina-
tion is beneficial since the same user
interface must accommodate young

Figure 8. Workflow of Inside Explorer, from initial data acquisition and curation in the collection phase, to exploration, where scientific discoveries and annotations are added to the data. Production designers then provide their interpretations in the production stage, further enhancing the data with stories and visual design. User feedback and interaction patterns are then collected during exhibition.

Illustration by Martin Falk.

EXHIBITIONPRODUCTIONEXPLORATIONCOLLECTION
DATA

Interaction patterns
User feedback
Scientific
Interpretations Initial data
documentation Stories

Figure 7. By providing interactive narrative exploration and information at key points of interest, museum visitors are free to explore the narrative at their own pace and in their own sequence. The broken bones in the shoulder of the Gebelein Man were not the only injury visitors discovered. The posterior part of the fourth rib was also damaged. This discovery revealed a 5,500-year-old murder.

Photo courtesy of Interactive Institute Swedish IC T / Interspectral.