Affording Design, Affording Redesign - Principia Designae: Pre-Design, Design, and Post-Design - page 91

had metaphors, like sharks, hands, boiling pots. The power of creating visual
explanations—sketches—seems to come from the natural mapping of parts and
relations among parts of the systems to the page. That mapping provides a check for
completeness, a check for coherence, and a platform for making inferences from
structure to behavior, process, causality.
7.2.6 Sketches Foster Collaboration
Sketches, as we have seen, make ideas public, the invisible visible. The external-
ization of thought onto paper, where it can be inspected and reinspected, eases
communication. Sketches are more permanent than speech, and ideas structured on
paper are more interpretable than ideas conveyed in words. They provide a physical
model that can be internalized to a mental one.
Sketches also allow easy embellishment with speech and gesture, to further
enhance communication. Because much essential information is there in the sketch,
that information doesn't have to be conveyed in awkward, clumsy speech. It can be
pointed to or gestured on, accompanied by deictic terms like “this,” or “that way,”
or “from here.” In one project, pairs of participants were given a hypothetical map
of a situation on campus after an earthquake, where some roads were closed, and
injured gathered at special places. Participants were asked to draw a new map
showing a route that would rescue the largest number of injured citizens as
efficiently as possible. Some pairs worked over the same map, so they could gesture
and see each others' gestures. Other pairs were separated by a curtain, so they could
easily hear each other, but not see each other. The pairs who could work together
over the same map produced far better new maps in less time, and were much
happier with the interaction (Heiser and Tversky 2004 ; Heiser et al. 2004 ). The
main kinds of gestures were pointing at landmarks (0-D), tracing paths (1-D), and
sweeping areas (2-D). These gestures served dual roles, a deictic role of pointing to
or indicating particular places and an iconic role, showing the shape of something.
The dependent measures here are the quality of the sketch maps, as rated by blind
judges, the subjective reports of the participants, and the analyses and comparisons
of the gestures and the accompanying speech for both groups of participants,
co-present and remote.
In this case, the gestures on the sketches were in the service of the design of a
route. There is every reason to believe that gestures and speech on sketches will
facilitate communication and joint design of other things. In fact, using an exter-
nalization of thought in the form of a sketch would seem to be especially effective
for more abstract ideas, which may be harder to grasp without a stable external
representation that provides some structure to the ideas.