Bringing the Physical to the Digital

This dissertation describes an exploration of digital tabletop interaction styles, with the ultimate goal of informing the design of a new model for tabletop interaction. In the context of this thesis the term digital tabletop refers to an emerging class of devices that afford many novel ways of interaction with the digital. Allowing users to directly touch information presented on large, horizontal displays. Being a relatively young field, many developments are in flux; hardware and software change at a fast pace and many interesting alternative approaches are available at the same time. In our research we are especially interested in systems that are capable of sensing multiple contacts (e.g., fingers) and richer information such as the outline of whole hands or other physical objects. New sensor hardware enable new ways to interact with the digital. When embarking into the research for this thesis, the question which interaction styles could be appropriate for this new class of devices was a open question, with many equally promising answers. Many everyday activities rely on our hands ability to skillfully control and manipulate physical objects. We seek to open up different possibilities to exploit our manual dexterity and provide users with richer interaction possibilities. This could be achieved through the use of physical objects as input mediators or through virtual interfaces that behave in a more realistic fashion. In order to gain a better understanding of the underlying design space we choose an approach organized into two phases. First, two different prototypes, each representing a specific interaction style – namely gesture-based interaction and tangible interaction – have been implemented. The flexibility of use afforded by the interface and the level of physicality afforded by the interface elements are introduced as criteria for evaluation. Each approaches’ suitability to support the highly dynamic and often unstructured interactions typical for digital tabletops is analyzed based on these criteria. In a second stage the learnings from these initial explorations are applied to inform the design of a novel model for digital tabletop interaction. This model is based on the combination of rich multi-touch sensing and a three dimensional environment enriched by a gaming physics simulation. The proposed approach enables users to interact with the virtual through richer quantities such as collision and friction. Enabling a variety of fine-grained interactions using multiple fingers, whole hands and physical objects. Our model makes digital tabletop interaction even more “natural”. However, because the interaction – the sensed input and the displayed output – is still bound to the surface, there is a fundamental limitation in manipulating objects using the third dimension. To address this issue, we present a technique that allows users to – conceptually – pick objects off the surface and control their position in 3D. Our goal has been to define a technique that completes our model for on-surface interaction and allows for “as-direct-as possible” interactions. We also present two hardware prototypes capable of sensing the users’ interactions beyond the table’s surface. Finally, we present visual feedback mechanisms to give the users the sense that they are actually lifting the objects off the surface. This thesis contributes on various levels. We present several novel prototypes that we built and evaluated. We use these prototypes to systematically explore the design space of digital tabletop interaction. The flexibility of use afforded by the interaction style is introduced as criterion alongside the user interface elements’ physicality. Each approaches’ suitability to support the highly dynamic and often unstructured interactions typical for digital tabletops are analyzed. We present a new model for tabletop interaction that increases the fidelity of interaction possible in such settings. Finally, we extend this model so to enable as direct as possible interactions with 3D data, interacting from above the table’s surface

Phrasing Bimanual Interaction for Visual Design

Architects and other visual thinkers create external representations of their ideas to support early-stage design. They compose visual imagery with sketching to form abstract diagrams as representations. When working with digital media, they apply various visual operations to transform representations, often engaging in complex sequences. This research investigates how to build interactive capabilities to support designers in putting together, that is phrasing, sequences of operations using both hands. In particular, we examine how phrasing interactions with pen and multi-touch input can support modal switching among different visual operations that in many commercial design tools require using menus and tool palettes—techniques originally designed for the mouse, not pen and touch. We develop an interactive bimanual pen+touch diagramming environment and study its use in landscape architecture design studio education. We observe interesting forms of interaction that emerge, and how our bimanual interaction techniques support visual design processes. Based on the needs of architects, we develop LayerFish, a new bimanual technique for layering overlapping content. We conduct a controlled experiment to evaluate its efficacy. We explore the use of wearables to identify which user, and distinguish what hand, is touching to support phrasing together direct-touch interactions on large displays. From design and development of the environment and both field and controlled studies, we derive a set methods, based upon human bimanual specialization theory, for phrasing modal operations through bimanual interactions without menus or tool palettes

Interactive natural user interfaces

For many years, science fiction entertainment has showcased holographic technology and futuristic user interfaces that have stimulated the world\u27s imagination. Movies such as Star Wars and Minority Report portray characters interacting with free-floating 3D displays and manipulating virtual objects as though they were tangible. While these futuristic concepts are intriguing, it\u27s difficult to locate a commercial, interactive holographic video solution in an everyday electronics store. As used in this work, it should be noted that the term holography refers to artificially created, free-floating objects whereas the traditional term refers to the recording and reconstruction of 3D image data from 2D mediums. This research addresses the need for a feasible technological solution that allows users to work with projected, interactive and touch-sensitive 3D virtual environments. This research will aim to construct an interactive holographic user interface system by consolidating existing commodity hardware and interaction algorithms. In addition, this work studies the best design practices for human-centric factors related to 3D user interfaces. The problem of 3D user interfaces has been well-researched. When portrayed in science fiction, futuristic user interfaces usually consist of a holographic display, interaction controls and feedback mechanisms. In reality, holographic displays are usually represented by volumetric or multi-parallax technology. In this work, a novel holographic display is presented which leverages a mini-projector to produce a free-floating image onto a fog-like surface. The holographic user interface system will consist of a display component: to project a free-floating image; a tracking component: to allow the user to interact with the 3D display via gestures; and a software component: which drives the complete hardware system. After examining this research, readers will be well-informed on how to build an intuitive, eye-catching holographic user interface system for various application arenas

Tailoring Interaction. Sensing Social Signals with Textiles.

Nonverbal behaviour is an important part of conversation and can reveal much about the nature of an interaction. It includes phenomena ranging from large-scale posture shifts to small scale nods. Capturing these often spontaneous phenomena requires unobtrusive sensing techniques that do not interfere with the interaction. We propose an underexploited sensing modality for sensing nonverbal behaviours: textiles. As a material in close contact with the body, they provide ubiquitous, large surfaces that make them a suitable soft interface. Although the literature on nonverbal communication focuses on upper body movements such as gestures, observations of multi-party, seated conversations suggest that sitting postures, leg and foot movements are also systematically related to patterns of social interaction. This thesis addressees the following questions: Can the textiles surrounding us measure social engagement? Can they tell who is speaking, and who, if anyone, is listening? Furthermore, how should wearable textile sensing systems be designed and what behavioural signals could textiles reveal? To address these questions, we have designed and manufactured bespoke chairs and trousers with integrated textile pressure sensors, that are introduced here. The designs are evaluated in three user studies that produce multi-modal datasets for the exploration of fine-grained interactional signals. Two approaches to using these bespoke textile sensors are explored. First, hand crafted sensor patches in chair covers serve to distinguish speakers and listeners. Second, a pressure sensitive matrix in custom-made smart trousers is developed to detect static sitting postures, dynamic bodily movement, as well as basic conversational states. Statistical analyses, machine learning approaches, and ethnographic methods show that by moni- toring patterns of pressure change alone it is possible to not only classify postures with high accuracy, but also to identify a wide range of behaviours reliably in individuals and groups. These findings es- tablish textiles as a novel, wearable sensing system for applications in social sciences, and contribute towards a better understanding of nonverbal communication, especially the significance of posture shifts when seated. If chairs know who is speaking, if our trousers can capture our social engagement, what role can smart textiles have in the future of human interaction? How can we build new ways to map social ecologies and tailor interactions

Physical Interaction Concepts for Knowledge Work Practices

The majority of workplaces in developed countries concern knowledge work. Accordingly, the IT industry and research made great efforts for many years to support knowledge workers -- and indeed, computer-based information workplaces have come of age. Nevertheless, knowledge work in the physical world has still quite a number of unique advantages, and the integration of physical and digital knowledge work leaves a lot to be desired. The present thesis aims at reducing these deficiencies; thereby, it leverages late technology trends, in particular interactive tabletops and resizable hand-held displays. We start from the observation that knowledge workers develop highly efficient practices, skills, and dexterity of working with physical objects in the real world, whether content-unrelated (coffee mugs, stationery etc.) or content-related (books, notepads etc.). Among the latter, paper-based objects -- the notorious analog information bearers -- represent by far the most relevant (super-) category. We discern two kinds of practices: collective practices concern the arrangement of objects with respect to other objects and the desk, while specific practices operate on individual objects and usually alter them. The former are mainly employed for an effective management of the physical desktop workspace -- e.g., everyday objects are frequently moved on tables to optimize the desk as a workplace -- or an effective organization of paper-based documents on the desktop -- e.g., stacking, fanning out, sorting etc. The latter concern the specific manipulation of physical objects related to the task at hand, i.e. knowledge work. Widespread assimilated practices concern not only writing on, annotating, or spatially arranging paper documents but also sophisticated manipulations -- such as flipping, folding, bending, etc. Compared to the wealth of such well-established practices in the real world, those for digital knowledge work are bound by the indirection imposed by mouse and keyboard input, where the mouse provided such a great advancement that researchers were seduced to calling its use "direct manipulation". In this light, the goal of this thesis can be rephrased as exploring novel interaction concepts for knowledge workers that i) exploit the flexible and direct manipulation potential of physical objects (as present in the real world) for more intuitive and expressive interaction with digital content, and ii) improve the integration of the physical and digital knowledge workplace. Thereby, two directions of research are pursued. Firstly, the thesis investigates the collective practices executed on the desks of knowledge workers, thereby discerning content-related (more precisely, paper-based documents) and content-unrelated object -- this part is coined as table-centric approaches and leverages the technology of interactive tabletops. Secondly, the thesis looks at specific practices executed on paper, obviously concentrating on knowledge related tasks due to the specific role of paper -- this part is coined as paper-centric approaches and leverages the affordances of paper-like displays, more precisely of resizable i.e. rollable and foldable displays. The table-centric approach leads to the challenge of blending interactive tabletop technology with the established use of physical desktop workspaces. We first conduct an exploratory user study to investigate behavioral and usage patterns of interaction with both physical and digital documents on tabletop surfaces while performing tasks such as grouping and browsing. Based on results of the study, we contribute two sets of interaction and visualization concepts -- coined as PaperTop and ObjecTop -- that concern specific paper based practices and collective practices, respectively. Their efficiency and effectiveness are evaluated in a series of user studies. As mentioned, the paper-centric perspective leverages late ultra-thin resizable display technology. We contribute two sets of novel interaction concepts again -- coined as FoldMe and Xpaaand -- that respond to the design space of dual-sided foldable and of rollout displays, respectively. In their design, we leverage the physical act of resizing not "just" for adjusting the screen real estate but also for interactively performing operations. Initial user studies show a great potential for interaction with digital contents, i.e. for knowledge work

The riddle of the mirror

The context of design is changing at a rapid pace. The impact of information technologies and digital creative tools continuously improving have revolutionized design practice. There has been a transition within the scope of a designer’s role - from simply giving form to a material to designing digital services. These developments have distanced design from tactile materiality. The designer, whose practice began as a material-based and rooted in the arts and crafts, must now rethink and reposition their creative processes and role within the current context of design. In this master thesis, I investigated this problem space by trying to answer the following research question: how does hands-on interaction with material influence the expressive and creative aspects of design practice? My method for investigating this research question is to engage in a practice-led research approach in which I explore the artistic potential of silver glass colors in glassblowing. I chose to research this topic in the field of glassblowing because of the intense physical interaction required between the artist and the material. In glassmaking, silver glass colors are used to create specific aesthetics, ranging from iridescent to silver mirrored surfaces. However, silver glass colors have been very challenging for many practitioners due to their unpredictable nature. I have considered this unpredictable material nature as a research opportunity to explore a reliable method of achieving silver mirrored results and to have artistic control of the wide metallic and iridescent palette. I have then applied these insights from material research to my artistic process and, with the help of relevant theory, I have reflected on both of these processes to investigate their intersection as a whole. My aim has been to determine the influence of hands-on material exploration on my design practice. The main findings are summarized in three points: 1) Hands-on interaction with the material has primarily influenced my early artistic vision and enhanced its expressive and creative aspects throughout my artistic production.2) Cyclical hands-on dialog with a material can support personal growth and help to develop an individual voice and creative expression; thus offering great potential for educational purposes. 3) The empirical data shows that silver glass colors provide a wide range of visual palette and can be preferred for local applications in particular, yet they require a long learning process to have control of them. This work provides information for readers who wish to know more about the role of hands-on studio practice and developing an individual voice through a creative process. Moreover, it presents helpful insights and data for people who are particularly interested in conducting material-based research in glassblowing and utilizing silver glass colors as an artistic technique