We explore making virtual desktops behave in a more physically realistic manner by adding physics simulation and using piling instead of filing as the fundamental organizational structure. Objects can be casually dragged and tossed around, influenced by physical characteristics such as friction and mass, much like we would manipulate lightweight objects in the real world. We present a prototype, called BumpTop, that coherently integrates a variety of interaction and visualization techniques optimized for pen input we have developed to support this new style of desktop organization.

On traditional tables, people frequently use the third dimension to pile, sort and store objects. However, while effective and informative for organization, this use of the third dimension does not usually extend far above the table. To enrich interaction with digital tables, we present the concept of shallow-depth 3D – 3D interaction with limited depth. Within this shallow-depth 3D environment several common interaction methods need to be reconsidered. Starting from any of one, two and three touch points, we present interaction techniques that provide control of all types of 3D rotation coupled with translation (6DOF) on a direct-touch tabletop display. The different techniques exemplify a wide range of interaction possibilities: from the one-touch technique, which is designed to be simple and natural, but inherits a degree of imprecision from its simplicity; through to three-touch interaction, which allows precise bimanual simultaneous control of multiple degrees of freedom, but at the cost of simplicity. To understand how these techniques support interaction in shallow-depth 3D, we present a user study that examines the efficiency of, and preferences for, the techniques developed. Results show that users are fastest and most accurate when using the three-touch technique and that their preferences were also strongly in favour of the expressive power available from three-touch. Author Keywords Shallow-depth 3D, tabletop display, direct-touch, rotation

Twenty years after the general adoption of overlapping windows and the desktop metaphor, modern window systems differ mainly in minor details such as window decorations or mouse and keyboard bindings. While a number of innovative window management techniques have been proposed, few of them have been evaluated and fewer have made their way into real systems. We believe that one reason for this is that most of the proposed techniques have been designed using a low fidelity approach and were never made properly available. In this paper, we present Metisse, a fully functional window system specifically created to facilitate the design, the implementation and the evaluation of innovative window management techniques. We describe the architecture of the system, some of its implementation details and present several examples that illustrate its potential.

We present ILoveSketch, a 3D curve sketching system that captures some of the affordances of pen and paper for professional designers, allowing them to iterate directly on concept 3D curve models. The system coherently integrates existing techniques of sketch-based interaction with a number of novel and enhanced features. Novel contributions of the system include automatic view rotation to improve curve sketchability, an axis widget for sketch surface selection, and implicitly inferred changes between sketching techniques. We also improve on a number of existing ideas such as a virtual sketchbook, simplified 2D and 3D view navigation, multi-stroke NURBS curve creation, and a cohesive gesture vocabulary. An evaluation by a professional designer shows the potential of our system for deployment within a real design process. ACM Classification: H.5.2 [Information Interfaces and

Many interactive surfaces have the ability to detect the shape of hands or objects placed on them. However, shape information is typically either condensed to individual contact points or categorized as discrete gestures. This does not leverage the full expressiveness of touch input, thus limits the actions users can perform in interactive applications. We present ShapeTouch, an exploration of interactions that directly utilize the contact shape on interactive surfaces to manipulations of objects and interactors. ShapeTouch infers virtual contact forces from contact regions and motion to enable interaction with virtual experiences of interacting with real physical objects. 1.

Copy-and-paste, one of the fundamental operations of modern user interfaces, can be performed through various means (e.g. using the keyboard, mouse-based direct manipulation or menus). When users copy and paste between two different windows, the process is complicated by window management tasks. In this paper, we propose two new window management techniques to facilitate these tasks in the particular case of partially overlapping windows. We describe an experiment comparing four commonly used copy-andpaste techniques under four window management conditions – non-overlapping windows, partially overlapping windows, and partially overlapping ones with one of our two window management techniques. Results show that our new window management techniques significantly reduce task completion time for all copy-and-paste techniques. They also show that X Window copy-and-paste is faster than the other three techniques under all four window management conditions.

Copy and move operations have long been supported by interactive desktops through various means. But the growing number of on-screen objects makes these means harder to use. In this note, we present new tools and techniques to enhance the existing ones: a selection, copy and drag history manager; two techniques to expose the user’s desk and leaf through stacks of overlapping windows; and a technique that integrates the previous two with conventional drag-anddrop. ACM Classification Keywords H.5.2 [Information interfaces and presentation]: User interfaces- Graphical user interfaces.

Treemaps provide an interesting solution for representing hierarchical data. However, most studies have mainly focused on layout algorithms and paid limited attention to the interaction with treemaps. This makes it difficult to explore large data sets and to get access to details, especially to those related to the leaves of the trees. We propose the notion of zoomable treemaps (ZTMs), an hybridization between treemaps and zoomable user interfaces that facilitates the navigation in large hierarchical data sets. By providing a consistent set of interaction techniques, ZTMs make it possible for users to browse through very large data sets (e.g., 700,000 nodes dispatched amongst 13 levels). These techniques use the structure of the displayed data to guide the interaction and provide a way to improve interactive navigation in treemaps.

We present the “boomerang ” technique, which makes it possible to suspend and resume drag-and-drop operations. A throwing gesture while dragging an object suspends the operation, anytime and anywhere. A drag-and-drop interaction, enhanced with our technique, allows users to switch windows, invoke commands, and even drag other objects during a drag-and-drop operation without using the keyboard or menus. We explain how a throwing gesture can suspend drag-and-drop operations, and describe other features of our technique, including grouping, copying, and deleting dragged objects. We conclude by presenting prototype implementations and initial feedback on the proposed technique. ACM Classification: H5.2 [Information interfaces and

For document visualization, folding techniques provide a focus-plus-context approach with fairly high legibility on flat sections. To enable richer interaction, we explore the design space of multi-touch document folding. We discuss several design considerations for simple modeless gesturing and compatibility with standard Drag and Pinch gestures. We categorize gesture models along the characteristics of Symmetric/Asymmetric and Serial/Parallel, which yields three gesture models. We built a prototype document workspace application that integrates folding and standard gestures, and a system for testing the gesture models. A user study was conducted to compare the three models and to analyze the factors of fold direction, target symmetry, and target tolerance in user performance when folding a document to a specific shape. Our results indicate that all three factors were significant for task times, and parallelism was greater for symmetric targets. Author Keywords Multi-touch screens, gesture input, document visualization.