Information Technology Reference
In-Depth Information
3.1 Pen-and-Paper User Interfaces (PPUIs)
One way to overcome the rupture between the paper world and the digital world
are Pen-and-Paper User Interfaces (PPUI). PPUIs are part of the larger class of user
interfaces which is called
post-desktop
or
post-WIMP
user interfaces. These inter-
faces go beyond the desktop metaphor and diverge from the “window, icon, menu,
pointing device” (WIMP) paradigm of classical Graphical User Interfaces. Van Dam
defines post-WIMP interfaces as “containing at least one interaction technique not
dependent on classical 2D widgets such as menus and icons” [21]. These inter-
faces build “on users' pre-existing knowledge of the everyday, non-digital world to
a much greater extent than before” [48].
PPUIs extend computing into the physical world by turning traditional paper
into a digital interactive medium. Pen-and-Paper User Interfaces (PPUIs) consist
of real paper and a pen whose movements are captured by the computer system.
This enables for instance transferring handwritings and drawings to a computer and
displaying a digital facsimile. Moreover, interactive elements of the user interface
can be printed onto paper. For example, paper sheets can contain printed interface
elements such as checkboxes, buttons, menus, fields for entering handwritten data
or fields for issuing commands by drawing specific symbols. By interacting with a
pen on these printed user interfaces, the user can control a digital system.
The basic setup of a PPUI is depicted in Figure 3.2. We distinguish two channels
1
that are indicated by the arrows.
Backend
system
Optional
digital feedback
Input
Optional
digital feedback
Input
(a) Data processing in a backend system
(b) Data processing on the pen
Fig. 3.2
Basic setup of a Pen-and-Paper User Interface from a user's perspective
1
A channel is realized by a physical device and transfers data from the user to the digital system
(input channel) or vice versa (output channel).
