Information Technology Reference
In-Depth Information
In contrast to general TUIs, research on Pen-and-Paper User Interfaces (PPUIs)
almost exclusively focused on developing new interaction techniques and systems.
A small number of publications took on a more theoretical point of view:
Guimbretiere introduces a lifecycle model of transformations between paper and
digital documents [32]. Although not presented as such, it is an important coun-
terpart to Ullmer and Ishii's interaction model [158], which was mentioned above.
Ullmer and Ishii model how
different
physical and digital representations are used
simultaneously in a complementing manner (e.g. a digital projection overlaying
physical building models). In contrast, Guimbretiere models how the
same
docu-
ment can be accessed in equivalent physical and digital representations. Depending
on the situation, the user chooses the representations that best fit his or her needs.
For example, in a mobile setting, the user might prefer reading and annotating a
printout of the document, while he or she prefers working with a digital represen-
tation for sharing it with co-workers. Offering the user both a physical and a digital
representation of the same information and letting the user choose between both of
them is a dimension which, to our knowledge, is not considered in the research on
general TUIs.
Yeh et al. [178] define a design space of paper interactions and present a toolkit
for the rapid development of PPUIs. The toolkit offers generic elements for printed
user interfaces, including input fields for handwritings and sketches, buttons and
check boxes. However, the underlying (implicit) interaction model focuses on inter-
actions with only single sheets of paper. It leaves aside the important dimension of
physical arrangements of pages and of interactions that span multiple pages (such
as Pick-and-Drop [122] and pen-based stitching gestures [37]).
Holman et al. [40] discuss how we might interact with documents on multiple
digital paper displays, which are light, flat and malleable like paper. They intro-
duce interaction primitives amongst others for activating and printing documents,
for copy&paste and for scrolling within documents. These interactions rely on phys-
ical manipulations of paper displays, such as picking them up, collocating, flipping
and stapling them, however not on pen-based interaction.
Finally, the iServer and iPaper framework [107] presents an extensive generic
model for links between physical and digital documents. However, it does not cover
specific interaction techniques.
This brief review showed that existing theory offers appropriate models for ana-
lyzing the interplay between physical and digital representations and for assessing
the relations between physical objects and the digital information they represent.
However, on the level of interactions, existing models do not sufficiently describe
Pen-and-Paper User Interfaces. As discussed above, models of Tangible User Inter-
faces consider only the interactions of displacing, rotating and arranging physical
objects while individual objects (e.g. shape, texture, content) are considered static.
In contrast, interaction with pen and paper comprises writing with a pen. This im-
plies that the tangible objects, i.e. the paper documents, themselves are altered.
An interaction model of Pen-and-Paper User Interfaces should identify generic
interaction primitives that are performed with pen and paper. A first step towards
these interaction primitives is the work by Yeh et al. [178]. However, this models
