Introduction - Human-Computer Interaction - page 15

contributes at filling this gap by sharpening the theoretical understanding of digital
interaction with pen and paper. On the one hand it supports the analysis of existing
user interfaces. On the other hand it provides systematic guidelines for the design of
novel interfaces that are easy to use, reliable and that can be seamlessly integrated
into existing work practices.
In three initial field studies, we have explored how paper and digital media are
used in knowledge acquisition processes. Based on the results of these studies, we
propose an ecological perspective as an appropriate theoretical position for the de-
sign of interactive paper systems. This perspective is based on Distributed Cognition
and on Information Ecologies and situates interaction within a collaborative work
context. This perspective is the basis for the actual interaction model. The model
systematically separates interaction into two levels: While the semantic level mod-
els what the user wants to perform with the interface, the syntactic level models
how this is achieved. This separation enables us to identify a set of generic interac-
tion primitives that can be performed with digital pen and paper. It will be demon-
strated that systems from related work can be classified in terms of these interaction
primitives. Moreover, these interaction primitives serve as building blocks of Pen-
and-Paper User Interfaces. By combining several interaction primitives, complex
paper-based user interfaces can be designed that offer a rich user experience while
remaining being both reliable and easy to use. This theoretical approach is at the
foundation of the novel interaction techniques, which are presented in the following
chapters.
Chapters 4-7 present the CoScribe concept for cross-media knowledge work with
documents. CoScribe is based on the theoretical interaction model of PPUIs and
proposes an integrated solution. Following an ecological model of knowledge work
as our guiding theory, CoScribe covers entire workflows in knowledge work and
puts strong emphasis on collaboration. Several persons can work at the same place
using multiple pens or can collaborate over a network connection.
Chapter 4 provides a high-level overview of the CoScribe concept. CoScribe
comprises a set of novel interaction techniques and visualizations for cross-media
knowledge work with documents. They focus on the cohabitation [32] of paper and
computers, i.e. both media are used in combination and treated at an equal footage.
These techniques and visualizations support several activities that are central for
effective knowledge acquisition. They enable users to annotate printed and digital
documents. Moreover, they allow users to generate structural knowledge of how
concepts of a domain are interrelated. This can be done by integrating documents
with hyperlinks and by translating contents into higher-level concepts with tags. In
terms of functionality, this is similar to Bush's vision of Memex [12], a machine that
supports reading and learning processes which are based on documents. In contrast
to Memex, the user cannot only work with documents which are displayed by a ma-
chine but also with printed documents. The interaction techniques offer a rich user
experience, being inspired by the traditional practices of using paper and relying
on such varied interactions as writing on paper, arranging several sheets of paper,
connecting paper sheets and attaching physical stickers. This varied user interface