Recent research in the area of immersive analytics demonstrated the utility of head-mounted augmented reality devices for visual data analysis. However, it can be challenging to use the by default supported mid-air gestures to interact with visualizations in augmented reality (e.g. due to limited precision). Touch-based interaction (e.g. via mobile devices) can compensate for these drawbacks, but is limited to two-dimensional input. In this work we present STREAM: Spatially-aware Tablets combined with Augmented Reality Head-Mounted Displays for the multimodal interaction with 3D visualizations. We developed a novel eyes-free interaction concept for the seamless transition between the tablet and the augmented reality environment. A user study reveals that participants appreciated the novel interaction concept, indicating the potential for spatially-aware tablets in augmented reality. Based on our findings, we provide design insights to foster the application of spatially-aware touch devices in augmented reality and research implications indicating areas that need further investigation.

Immersive technologies such as augmented reality devices are opening up a new design space for the visual analysis of data. This paper studies the potential of an augmented reality environment for the purpose of collaborative analysis of multidimensional, abstract data. We present ART, a collaborative analysis tool to visualize multidimensional data in augmented reality using an interactive, 3D parallel coordinates visualization. The visualization is anchored to a touch-sensitive tabletop, benefiting from well-established interaction techniques. The results of group-based, expert walkthroughs show that ART can facilitate immersion in the data, a fluid analysis process, and collaboration. Based on the results, we provide a set of guidelines and discuss future research areas to foster the development of immersive technologies as tools for the collaborative analysis of multidimensional data.

Augmented Reality (AR) displays have been suggested as shared-space technology to support remote collaboration, e.g., in design and building tasks. But with AR displays, the shared space typically consists of only the virtual work objects (e.g., design artifacts) while collaborators' interaction is grounded in their individual, physical environment. This can become problematic during activities that involve the positioning of virtual objects because the collaborators may require shared spatial references to coordinate their actions. In a lab experiment with 16 dyads, we studied how collaborators deal with that issue, and whether the provisioning of additive, virtual landmarks influences collaboration. As a result the landmarks improved user experience and decreased the reported temporal demand. In addition, we identified task-specific problem situations and provide implications for the design of distributed ARs to facilitate the collaborative positioning of virtual objects.

Distortion-based visualization techniques allow users to examine focused regions of a multiscale space at high scales but preserve their contextual information. However, the distortion can come at the coast of confusion, disorientation and impairment of the users' spatial memory. Yet, how distortions influence users' ability to build up spatial memory, while taking into account human skills of perception, interpretation and comprehension, remains underexplored. This note reports findings of an experimental comparison between a distortion-based focus+context interface and an undistorted overview+detail interface. The focus+context technique follows guidelines for the design of comprehensible distortions: make use of real-world metaphors, visual clues like shading, smooth transitions and scaled-only focus regions. The results show that the focus+context technique designed following these guidelines help to keep track of the position within the multiscale space and does not impair users' spatial memory.

OPAC interfaces, still the dominant access point to library catalogs, support systematic search but are problematic for open-ended exploration and generally unpopular with visitors. As a result, libraries start subscribing to simplified search paradigms as exemplified by web-search systems. This is a problem considering that systematic search is a crucial skill in the light of today's abundance of digital information. Inspired by novel approaches to facilitating search, we designed CollectionDiver, an installation for supporting systematic search in public libraries. The CollectionDiver combines tangible and large display direct-touch interaction with a visual representation of search criteria and filters. We conducted an in-situ qualitative study to compare participants' search approaches on the CollectionDiver with those on the OPAC interface. Our findings show that while both systems support a similar search process, the CollectionDiver (1) makes systematic search more accessible, (2) motivates proactive search approaches by (3) adding transparency to the search process, and (4) facilitates shared search experiences. We discuss the CollectionDiver's design concepts to stimulate new ideas toward supporting engaging approaches to systematic search in the library context and beyond.

Many tasks performed in multiscale visual spaces require the user to have several foci. Using bimanual interaction, multitouch devices can facilitate the simultaneous definition and exploration of several foci. However, multitouch is rarely used for multifocus navigation, and may limit the interaction to a sequential definition of areas of interest. We introduce two novel navigation techniques that combine multiple foci and bimanual touch, and therefore enable the isochronic definition of areas of interest, leading to simultaneous multifocus navigation. SpaceFold folds the visual space in the third dimension, allowing users to bring objects closer to each other. Our technique enables a direct, bimanual manipulation of a folded space and therefore provides high flexibility. PhysicLenses uses multiple magnification lenses to compare objects. Using a physics model, PhysicLenses introduces a general solution for the arrangement of multiple lenses within the viewport. We conducted a controlled experiment with 24 participants to compare the techniques with split screen. The results show that SpaceFold significantly outperformed all other techniques, whereas PhysicLenses was just as fast as split screen.

In today's digital control rooms, desktop computers represent the most common interface for process control. Compared to their predecessors -- manual control actuators -- desktop computers enable quick and effective process intervention but they lack in process-related interaction qualities such as haptic feedback and the involvement of motor skills. Thus, design trade-offs have to be made to combine the strengths of both paradigms: today's processing power with the interaction qualities of former control room interfaces. In this paper related interaction concepts are presented and evaluated. In a control room scenario, participants were tasked with adjusting numerical values -- so-called process variables -- under two traditional conditions (mouse, keyboard) and two post-WIMP conditions (touch, tangible). Task completion time and recall accuracy of the adjusted values were measured. As a result, traditional desktop interaction proved to be faster, whereas control actions could be recalled significantly better using the tangible control elements. We therefore suggest providing both tangible control for process maintenance and traditional desktop interaction in critical situations that require quick intervention.

Context-sensitive information is of vital importance to the monitoring of processes in control rooms, but its incorporation in current state-of-the-art user interfaces is inadequate. By looking at a traffic control center as an example, this paper proposes an interaction concept for monitoring complex networks on large remote displays. Our approach is based on content-aware navigation with the goal to improve the navigation of the road network and the availability of context-sensitive information. We conducted a study comparing different navigation techniques as well as two techniques for visualizing context-sensitive information.