coupled vertical display, combines digital pen and paper notes (see www.anoto.com), tangible tools, and multitouch interaction techniques to replicate many of the crucial qualities of material artifacts.

At the same time, it extends the traditional methods by providing functionalities that complement the original workflow, such as image retrieval based on handwritten text, search functions, highlighting of artifacts for discussion, and more efficient clustering mechanisms. In our user studies we could confirm the benefits of physical material, in particular for externalization activities, while we found that digital functionality was especially useful in convergent activities like sense-making and discussion.

Collaborative thinking with interactive display space. As outlined here, display space and spatial arrangements of artifacts are important tools for thinking and communication within a design team. By leveraging the ability to physically align, juxtapose, and compare different artifacts in space, designers harness their spatial thinking abilities. Consequently, it may also be valuable to explore the role of digital display space for use in collaborative design activities. As multi-display environments and large interactive displays such as interactive whiteboards, multitouch tables, and wallsize screens become increasingly available, this ecology of screens can be used to augment the spatial nature of design practice. In the past we have seen significant advances in integrating displays into a larger infrastructure, such as rooms or furniture, to support more creative work styles and collaborative sense-making. In these systems, interactive displays are used for presenting, discussing, and annotating artifacts during meetings [ 1].

In our research we also explored the role that multiple displays can play in navigation and spatial positioning of digital design artifacts [ 5]. In our Affinity Table system, we coupled two large displays within a virtual workspace, which enables us to provide multiple views on collections of digital artifacts. For example, we display a detailed view of notes on the table, while the vertical display presents an overview of all available notes, thereby facilitating an overview on the progress of the design activity (see Figure 2, top). As a result of this division, we also implicitly assigned roles to these workspaces, with the table primarily used for manipulations (action space), while the vertical display supports reflection activities (reflection space). Furthermore, we designed tangible tools that can be used for generating dynamic views of groups of artifacts. By selecting a region on the table with a token object, this area within the virtual workspace is then enlarged on the wall display (see Figure 2, bottom). This zooming functionality can further be refined by turning the token to increase or decrease the degree of magnification. Designers may use this functionality to focus on specific artifacts during discussion. From our experiences, the dynamic nature of interactive displays can be used to augment our spatial-think-ing abilities and aid group coordination and awareness. This allows us not only to imitate the spatial characteristics of traditional practice but also to go beyond what is possible with material artifacts.

Reflecting by capturing and visualizing the design process. Our physical design practice has a lot of benefits but also some drawbacks. One of the most crucial drawbacks is the tremendous effort required for documenting, archiving, and sharing

March + April 2012