Harald Reiterer

Fluid interaction for information visualization

Despite typically receiving little emphasis in visualization research, interaction in visualization is the catalyst for the users dialogue with the data, and, ultimately, the users actual understanding and insight into these data. There are many possible reasons for this skewed balance between the visual and interactive aspects of a visualization. One reason is that interaction is an intangible concept that is difficult to design, quantify, and evaluate. Unlike for visual design, there are few examples that show visualization practitioners and researchers how to design the interaction for a new visualization in the best manner. In this article, we attempt to address this issue by collecting examples of visualizations with ‘best-in-class’ interaction and using them to extract practical design guidelines for future designers and researchers. We call this concept fluid interaction, and we propose an operational definition in terms of the direct manipulation and embodied interaction paradigms, the psychological concept of ‘flow’, and Normans gulfs of execution and evaluation.

HuddleLamp: Spatially-Aware Mobile Displays for Ad-hoc Around-the-Table Collaboration

We present HuddleLamp, a desk lamp with an integrated RGB-D camera that precisely tracks the movements and positions of mobile displays and hands on a table. This enables a new breed of spatially-aware multi-user and multi-device applications for around-the-table collaboration without an interactive tabletop. At any time, users can add or remove displays and reconfigure them in space in an ad-hoc manner without the need of installing any software or attaching markers. Additionally, hands are tracked to detect interactions above and between displays, enabling fluent cross-device interactions. We contribute a novel hybrid sensing approach that uses RGB and depth data to increase tracking quality and a technical evaluation of its capabilities and limitations. For enabling installation-free ad-hoc collaboration, we also introduce a web-based architecture and JavaScript API for future HuddleLamp applications. Finally, we demonstrate the resulting design space using five examples of cross-device interaction techniques.

IPSep-CoLa: An Incremental Procedure for Separation Constraint Layout of Graphs

We extend the popular force-directed approach to network (or graph) layout to allow separation constraints, which enforce a minimum horizontal or vertical separation between selected pairs of nodes. This simple class of linear constraints is expressive enough to satisfy a wide variety of application-specific layout requirements, including: layout of directed graphs to better show flow; layout with non-overlapping node labels; and layout of graphs with grouped nodes (called clusters). In the stress majorization force-directed layout process, separation constraints can be treated as a quadratic programming problem. We give an incremental algorithm based on gradient projection for efficiently solving this problem. The algorithm is considerably faster than using generic constraint optimization techniques and is comparable in speed to unconstrained stress majorization. We demonstrate the utility of our technique with sample data from a number of practical applications including gene-activation networks, terrorist networks and visualization of high-dimensional data.Existing information-visualization techniques that target small screens are usually limited to exploring a few hundred items. In this article we present a scatterplot tool for personal digital assistants that allows the handling of many thousands of items. The applications scalability is achieved by incorporating two alternative interaction techniques: a geometric-semantic zoom that provides smooth transition between overview and detail, and a fisheye distortion that displays the focus and context regions of the scatterplot in a single view. A user study with 24 participants was conducted to compare the usability and efficiency of both techniques when searching a book database containing 7500 items. The study was run on a pen-driven Wacom board simulating a PDA interface. While the results showed no significant difference in task-completion times, a clear majority of 20 users preferred the fisheye view over the zoom interaction. In addition, other dependent variables such as user satisfaction and subjective rating of orientation and navigation support revealed a preference for the fisheye distortion. These findings partly contradict related research and indicate that, when using a small screen, users place higher value on the ability to preserve navigational context than they do on the ease of use of a simplistic, metaphor-based interaction style

NAVI: a proof-of-concept of a mobile navigational aid for visually impaired based on the microsoft kinect

We present a proof-of-concept of a mobile navigational aid that uses the Microsoft Kinect and optical marker tracking to help visually impaired people find their way inside buildings. The system is the result of a student project and is entirely based on low-cost hard- and software. It provides continuous vibrotactile feedback on the persons waist, to give an impression of the environment and to warn about obstacles. Furthermore, optical markers can be used to tag points of interest within the building to enable synthesized voice instructions for point-to-point navigation.

Software Evaluation using the 9241 Evaluator

Abstract There is an increasing need for practical and comprehensive evaluation methods and tools for conformance testing with ISO standards.In this study, we focus on ISO9241 which is an important ergonomic standard. A brief description shows its content and structure. Practical evaluations include the amount of time and resources which must be managed in software projects,while comprehensive evaluations require that the context of use be considered during the evaluation of user interfaces. In order to complete a comprehensive evaluation of usability, it is necessary to use more than one evaluation method. Therefore, an overview of different evaluation approaches is given, describing their advantages and disadvantages. Finally, the ISO 9241 evaluator is presented in detail as an example of a practical expert-based evaluation method for conformance testing with the ISO 9241 standard, that can be integrated in a comprehensive evaluation approach.

Squidy: a zoomable design environment for natural user interfaces

We introduce the interaction library Squidy, which eases the design of natural user interfaces by unifying relevant frameworks and toolkits in a common library. Squidy provides a central design environment based on high-level visual data flow programming combined with zoomable user interface concepts. The user interface offers a simple visual language and a collection of ready-to-use devices, filters and interaction techniques. The concept of semantic zooming enables nevertheless access to more advanced functionality on demand. Thus, users are able to adjust the complexity of the user interface to their current need and knowledge.

INSYDER — an information assistant for business intelligence

The WWW is the most important resource for external business information. This paper presents a tool called INSYDER, an information assistant for finding and analysis business information from the WWW. INSYDER is a system using different agents for crawling the Web, evaluating and visualising the results. These agents, the used visualisations, and a first summary of user studies are presented.

Designing reality-based interfaces for creative group work

Using affinity diagramming as an example, we investigate reality-based interfaces for supporting creative group work. Based on an observational study grounded in the reality-based interaction framework, we identified power vs. reality tradeoffs that can be addressed to find a close fit to embodied practice. Using this knowledge, we designed and implemented a digital workspace for supporting affinity diagramming. Its hybrid interaction techniques combine digital pen & paper with an interactive table and tangible tokens. An additional vertical display is used to support reflection-in-action and for enhancing discussion and coordination. A preliminary user study confirmed the applicability of our tradeoffs and the general acceptance of the tool design.

Interactive Design of Multimodal User Interfaces

In contrast to the pioneers of multimodal interaction, e.g. Richard Bolt in the late seventies, today’s researchers can benefit from various existing hardware devices and software toolkits. Although these development tools are available, using them is still a great challenge, particularly in terms of their usability and their appropriateness to the actual design and research process. We present a three-part approach to supporting interaction designers and researchers in designing, developing, and evaluating novel interaction modalities including multimodal interfaces. First, we present a software architecture that enables the unification of a great variety of very heterogeneous device drivers and special-purpose toolkits in a common interaction library named “Squidy”. Second, we introduce a visual design environment that minimizes the threshold for its usage (ease-of-use) but scales well with increasing complexity (ceiling) by combining the concepts of semantic zooming with visual dataflow programming. Third, we not only support the interactive design and rapid prototyping of multimodal interfaces but also provide advanced development and debugging techniques to improve technical and conceptual solutions. In addition, we offer a test platform for controlled comparative evaluation studies as well as standard logging and analysis techniques for informing the subsequent design iteration. Squidy therefore supports the entire development lifecycle of multimodal interaction design, in both industry and research.

Blended Interaction: understanding natural human---computer interaction in post-WIMP interactive spaces

We introduce Blended Interaction, a new conceptual framework that helps to explain when users perceive user interfaces as “natural” or not. Based on recent findings from embodied cognition and cognitive linguistics, Blended Interaction provides a novel and more accurate description of the nature of human–computer interaction (HCI). In particular, it introduces the notion of conceptual blends to explain how users rely on familiar and real-world concepts whenever they learn to use new digital technologies. We apply Blended Interaction in the context of post-“Windows Icons Menu Pointer” interactive spaces. These spaces are ubiquitous computing environments for computer-supported collaboration of multiple users in a physical space or room, e.g., meeting rooms, design studios, or libraries, augmented with novel interactive technologies and digital computation, e.g., multi-touch walls, tabletops, and tablets. Ideally, in these spaces, the virtues of the familiar physical and social world are combined with that of the digital realm in a considered manner so that desired properties of each are preserved and a seemingly “natural” HCI is achieved. To support designers in this goal, we explain how the users’ conceptual systems use blends to tie together familiar concepts with the novel powers of digital computation. Furthermore, we introduce four domains of design to structure the underlying problem and design space: individual and social interaction, workflow, and physical environment. We introduce our framework by discussing related work, e.g., metaphors, mental models, direct manipulation, image schemas, reality-based interaction, and illustrate Blended Interaction using design decisions we made in recent projects.