Information Technology Reference
In-Depth Information
in physical space. This results in more intuitive interfaces that moreover can be
flexibly adapted to the current work situation by arranging tangible tools accord-
ingly.
4.
Cope with the restricted feedback capabilities of paper
A major challenge for the design of PPUIs is the very restricted feedback capa-
bilities that we are facing when using paper as an interactive medium. First and
foremost, the designer should identify interactions that leverage feedback which
is provided by the physical properties of paper instead of digital real-time feed-
back which must be provided by the system. For instance, writing on a sheet of
paper generates “real-time feedback” by leaving visible ink traces; attaching an
index sticker generates feedback in form of a sticker which is visible on paper.
Second, the design should avoid temporal modes if the current mode cannot be
clearly and continuously communicated to the user. Instead, the design should
leverage spatial multiplexing or device multiplexing - this provides for “modes”
which the user can clearly recognize as such without digital feedback. Third, the
design should make careful use of handwriting recognition and gesture recogni-
tion. These should be used as a central part of the interaction design only if the
recognition does not imply uncertainty or if real-time feedback on the recogni-
tion result can be given to the user. Finally, if digital real-time feedback should
be provided, the designer should choose an appropriate channel following the
four-dimensional taxonomy of our model (temporal/spatial distance, modality,
data rate).
5.
Leave interactional freedom to the user
Since the practices of working with pen and paper are highly informal and indi-
vidual, PPUIs should leave much freedom to the user and impose only minimal
constraints on traditional, well-established practices.
In the next chapters, we will integrate the findings presented in the first three
chapters of this topic, moving on from the analytical and model-centered point
of view to a design perspective. We will apply the theoretical model, which was
presented in this chapter, and contribute novel interaction techniques and a system
framework for paper-based knowledge work.
