Mark S. Hancock

Shallow-depth 3d interaction: design and evaluation of one-, two- and three-touch techniques

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.

Sticky tools: full 6DOF force-based interaction for multi-touch tables

Tabletop computing techniques are using physically familiar force-based interactions to enable compelling interfaces that provide a feeling of being embodied with a virtual object. We introduce an interaction paradigm that has the benefits of force-based interaction complete with full 6DOF manipulation. Only multi-touch input, such as that provided by the Microsoft Surface and the SMART Table, is necessary to achieve this interaction freedom. This paradigm is realized through sticky tools: a combination of sticky fingers, a physically familiar technique for moving, spinning, and lifting virtual objects; opposable thumbs, a method for flipping objects over; and virtual tools, a method for propagating behaviour to other virtual objects in the scene. We show how sticky tools can introduce richer meaning to tabletop computing by drawing a parallel between sticky tools and the discussion in Urp [20] around the meaning of tangible devices in terms of nouns, verbs, reconfigurable tools, attributes, and pure objects. We then relate this discussion to other force-based interaction techniques by describing how a designer can introduce complexity in how people can control both physical and virtual objects, how physical objects can control both physical and virtual objects, and how virtual objects can control virtual objects.

Heuristics for information visualization evaluation

Heuristic evaluation is a well known discount evaluation technique in human-computer interaction (HCI) but has not been utilized in information visualization (InfoVis) to the same extent. While several sets of heuristics have been used or proposed for InfoVis, it is not yet known what kind of heuristics are useful for finding general InfoVis problems. We performed a meta-analysis with the goal of exploring the issues of heuristic evaluation for InfoVis. This meta-analysis concentrates on issues pertaining to the selection and organization of heuristics, and the process itself. For this purpose, we used three sets of previously published heuristics to assess a visual decision support system that is used to examine simulation data. The meta-analysis shows that the evaluation process and results have a high dependency on the heuristics and the types of evaluators chosen. We describe issues related to interpretation, redundancy, and conflict in heuristics. We also provide a discussion of generalizability and categorization of these heuristics.

Haptic Retargeting: Dynamic Repurposing of Passive Haptics for Enhanced Virtual Reality Experiences

Manipulating a virtual object with appropriate passive haptic cues provides a satisfying sense of presence in virtual reality. However, scaling such experiences to support multiple virtual objects is a challenge as each one needs to be accompanied with a precisely-located haptic proxy object. We propose a solution that overcomes this limitation by hacking human perception. We have created a framework for repurposing passive haptics, called haptic retargeting, that leverages the dominance of vision when our senses conflict. With haptic retargeting, a single physical prop can provide passive haptics for multiple virtual objects. We introduce three approaches for dynamically aligning physical and virtual objects: world manipulation, body manipulation and a hybrid technique which combines both world and body manipulation. Our study results indicate that all our haptic retargeting techniques improve the sense of presence when compared to typical wand-based 3D control of virtual objects. Furthermore, our hybrid haptic retargeting achieved the highest satisfaction and presence scores while limiting the visible side-effects during interaction.

Examination of Text-Entry Methods for Tabletop Displays

Although text entry is a vital part of day-to-day computing familiar to most people, not much research has been done to enable text entry on large interactive tables. One might assume that a good approach would be to choose an existing technique known to be fast, ergonomic, and currently preferred by the general population, but there are many additional factors to consider in this specific domain. We consider a variety of existing text-entry methods and examine their viability for use on tabletop displays. We discuss these techniques not only in terms of their general characteristics, performance, and adoption, but introduce other evaluative criteria, including: environmental factors unique to large digital tables and the support for multi-user simultaneous interaction. Based on our analysis we illustrate by example how to choose appropriate text-entry methods for tabletop applications with differing requirements, whether by selection from existing methods, or through a combination of desirable elements from a variety of methods. Our criteria can also be used as heuristics during the iterative design of a completely new text-entry technique.

Improving menu placement strategies for pen input

We investigate menu selection in circular and rectangular pop-up menus using stylus-driven direct input on horizontal and vertical display surfaces. An experiment measured performance in a target acquisition task in three different conditions: direct input on a horizontal display surface, direct input on a vertical display and indirect input to a vertical display. The third condition allows comparison of direct and indirect techniques commonly used for vertical displays. The results of the study show that both left-handed and right-handed users demonstrate a consistent, but mirrored pattern of selection times that is corroborated by qualitative measures of user preference. We describe a menu placement strategy for a tabletop display that detects the handedness of the user and displays rectangular pop-up menus. This placement is based on the results of our study.

Exploring 3D Interaction in Alternate Control-Display Space Mappings

The desire to have intuitive, seamless 3D interaction fuels research exploration into new approaches to 3D interaction. However, within these explorations we continue to rely on Brunelleschis perspective for display and map the interactive control space directly into it without much thought on the effect that this default mapping has. In contrast, there are many possibilities for creating 3D interaction spaces, thus making it important to run user studies to examine these possibilities. Options in mapping the control space to the display space for 3D interaction have previously focused on the manipulation of control-display ratio or gain. In this paper, we present a conceptual framework that provides a more general control-display description that includes mappings for flip, rotation, skew, as well as scale (gain). We conduct a user study to explore 3D selection and manipulation tasks in three of these different mappings in comparison to the commonly used mapping (perspective mapping of control space to a perspective display). Our results show interesting differences between interactions and user preferences in these mappings and indicate that all may be considered viable alternatives. Together this framework and study open the door to further exploration of 3D interaction variations

Supporting sandtray therapy on an interactive tabletop

We present the iterative design of a virtual sandtray application for a tabletop display. The purpose of our prototype is to support sandtray therapy, a form of art therapy typically used for younger clients. A significant aspect of this therapy is the insight gained by the therapist as they observe the client interact with the figurines they use to create a scene in the sandtray. In this manner, the therapist can gain increased understanding of the clients psyche. We worked with three sandtray therapists throughout the evolution of our prototype. We describe the details of the three phases of this design process: initial face-to-face meetings, iterative design and development via distance collaboration, and a final face-to-face feedback session. This process revealed that our prototype was sufficient for therapists to gain insight about a persons psyche through their interactions with the virtual sandtray.

Exploring tangible and direct touch interfaces for manipulating 2D and 3D information on a digital table

On traditional tables, people often manipulate a variety of physical objects, both 2D in nature (e.g., paper) and 3D in nature (e.g., books, pens, models, etc.). Current advances in hardware technology for tabletop displays introduce the possibility of mimicking these physical interactions through direct-touch or tangible user interfaces. While both promise intuitive physical interaction, they are rarely discussed in combination in the literature. In this paper, we present a study that explores the advantages and disadvantages of tangible and touch interfaces, specifically in relation to one another. We discuss our results in terms of how effective each technique was for accomplishing both a 3D object manipulation task and a 2D information visualization exploration task. Results suggest that people can more quickly move and rotate objects in 2D with our touch interaction, but more effectively navigate the visualization using tangible interaction. We discuss how our results can be used to inform future designs of tangible and touch interaction.

Territoriality and behaviour on and around large vertical publicly-shared displays

We investigate behaviours on, and around, large vertical displays during concurrent usage. Using an observational field study, we identify fundamental patterns of how people use existing public displays: their orientation, positioning, group identification, and behaviour within and between social groups just-before, during, and just-after usage. These results are then used to motivate a controlled experiment where two individuals or two pairs of individuals complete tasks concurrently on a simulated large vertical display. Results from our controlled study demonstrates that vertical surface territories are similar to those found in horizontal tabletops in function, but their definitions and social conventions are different. In addition, the nature of use-while-standing systems results in more complex and dynamic physical territories around the display. We show that the anthropological notion of personal space must be slightly refined for application to vertical displays.