Chair: Chris Harrison, Carnegie Mellon University, USA
Going Beyond the Surface: Studying Multi-Layer Interaction Above the Tabletop
Contribution & Benefit: Presents guidelines for designers of Tangible Magic Lens systems that are targeted for a tabletop environment. Can assist in developing effective multi-layer based interaction styles.
Abstract » Lightweight spatially aware displays (Tangible Magic Lenses) are an effective approach for exploring complex information spaces within a tabletop environment. One way of using the 3D space above a horizontal surface is to divide it into discrete parallel layers stacked upon each other. Horizontal and vertical lens movements are essential tasks for the style of multi-layer interaction associated with it. We conducted a comprehensive user study with 18 participants investigating fundamental issues such as optimal number of layers and their thickness, movement and holding accuracies, and physical boundaries of the interaction volume. Findings include a rather limited overall interaction height (44 cm), a different minimal layer thickness for vertical and horizontal search tasks (1 cm/4 cm), a reasonable maximum number of layers depending on the primary task, and a convenience zone in the middle for horizontal search. Derived from that, design guidelines are also presented.ACM
A Comparative Evaluation of Finger and Pen Stroke Gestures
Contribution & Benefit: First study investigating the differences and similarities between finger and pen gestures. Can assist UI designers of finger-based gesture design in applying the principles, methods and findings in our study.
Abstract » This paper reports an empirical investigation in which participants produced a set of stroke gestures with varying degrees of complexity and in different target sizes using both the finger and the pen. The recorded gestures were then analyzed according to multiple measures characterizing many aspects of stroke gestures. Our findings were as follows: (1) Finger drawn gestures were quite different to pen drawn gestures in basic measures including size ratio and average speed. Finger drawn gestures tended to be larger and faster than pen drawn gestures. They also differed in shape geometry as measured by, for example, aperture of closed gestures, corner shape distance and intersecting points deviation; (2) Pen drawn gestures and finger drawn gestures were similar in several measures including articulation time, indicative angle difference, axial symmetry and proportional shape distance; (3) There were interaction effects between gesture implement (finger vs. pen) and target gesture size and gesture complexity. Our findings show that half of the features we tested were performed well enough by the finger. This finding suggests that "finger friendly" systems should exploit these features when designing finger interfaces and avoid using the other features in which the finger does not perform as well as the pen.ACM
A Handle Bar Metaphor for Virtual Object Manipulation with Mid-Air Interaction
Contribution & Benefit: A novel handle bar metaphor is proposed to realise a suite of intuitive and highly-controllable mid-air interaction for manipulating single/multiple virtual 3D objects with low-resolution depth sensors like Kinect
Abstract » Commercial 3D scene acquisition systems such as the Microsoft Kinect sensor can reduce the cost barrier of realizing mid-air interaction. However, since it can only sense hand position but not hand orientation robustly, current mid-air interaction methods for 3D virtual object manipulation often require contextual and mode switching to perform translation, rotation, and scaling, thus preventing natural continuous gestural interactions. A novel handle bar metaphor is proposed as an effective visual control metaphor between the user's hand gestures and the corresponding virtual object manipulation operations. It mimics a familiar situation of handling objects that are skewered with a bimanual handle bar. The use of relative 3D motion of the two hands to design the mid-air interaction allows us to provide precise controllability despite the Kinect sensor's low image resolution. A comprehensive repertoire of 3D manipulation operations is proposed to manipulate single objects, perform fast constrained rotation, and pack/align multiple objects along a line. Three user studies were devised to demonstrate the efficacy and intuitiveness of the proposed interaction techniques on different virtual manipulation scenarios.ACM
Fly: Studying Recall, Macrostructure Understanding, and User Experience of Canvas Presentations
Contribution & Benefit: Presents a user study to investigate the effect of the canvas presentation format on recall, macrostructure understanding, and user experience.
Abstract » Most presentation software uses the slide deck metaphor to create visual presentation support. Recently, canvas presentation tools such as Fly or Prezi have begun to use a zoomable free-form canvas to arrange information instead. While their effect on authoring presentations has been evaluated previously, we studied how they impact the audience. In a quantitative study, we compared audience retention and macrostructure understanding of slide deck vs. canvas presentations. We found both approaches to be equally capable of communicating information to the audience. Canvas presentations, however, were rated by participants to better aid them in staying oriented during a talk. This makes canvas presentation tools a promising slideware alternative.ACM