Handoff is a synchronous object transfer technique in face-to-face collaborative work and is one of the low-level actions of collaboration that is smooth and natural in physical settings; however, in digital tabletop workspaces, digital handoff is often awkward and difficult to control. We carried out a series of studies to investigate how digital handoff could be improved in tabletop systems. We first observed people doing several real-world tasks around a standard table and found that handoff is as common in the real-world as deposit (an asynchronous tool transfer technique). The study identified several guidelines to support the design of handoff actions in digital tabletop system. We then examined 2D-handoff techniques; by running a pilot study, we compared the traditional handoff technique with the real-world tangible handoff technique, and found that the traditional digital handoff technique was not well suited for transferring objects on the tabletop. By analyzing the handoff mechanism we spot the bottleneck that affected traditional handoff procedures and designed a novel 2D-handoff technique, force-field technique, which alleviated this bottle-neck to solve this problem. Through a user-study we found that the force-field technique was significantly faster than current digital handoff techniques and as good as real-world 2D-handoff techniques. In addition, force-field handoff was most preferred by a majority of participants. We further designed and implemented a 3D-handoff technique that embodies our observations of how handoff occurs in the real-world setting. <p>Finally, we evaluated our design in a simulated digital-tabletop task with the goal of assessing the usefulness of various digital transfer techniques including standard deposit, traditional handoff, force-field and 3D-handoff. The results showed that on the digital tabletop system the percentage of using deposit, 2D-handoff and 3D-handoff techniques is similar with the percentage of using these techniques on the real world physical table. 3D-handoff was the most preferred and the most frequently used technique among the handoff techniques; and the force-field technique is preferred than traditional handoff technique.

Handoff is a synchronous object transfer technique in face-to-face collaborative work and is one of the low-level actions of collaboration that is smooth and natural in physical settings; however, in digital tabletop workspaces, digital handoff is often awkward and difficult to control. We carried out a series of studies to investigate how digital handoff could be improved in tabletop systems. We first observed people doing several real-world tasks around a standard table and found that handoff is as common in the real-world as deposit (an asynchronous tool transfer technique). The study identified several guidelines to support the design of handoff actions in digital tabletop system. We then examined 2D-handoff techniques; by running a pilot study, we compared the traditional handoff technique with the real-world tangible handoff technique, and found that the traditional digital handoff technique was not well suited for transferring objects on the tabletop. By analyzing the handoff mechanism we spot the bottleneck that affected traditional handoff procedures and designed a novel 2D-handoff technique, force-field technique, which alleviated this bottle-neck to solve this problem. Through a user-study we found that the force-field technique was significantly faster than current digital handoff techniques and as good as real-world 2D-handoff techniques. In addition, force-field handoff was most preferred by a majority of participants. We further designed and implemented a 3D-handoff technique that embodies our observations of how handoff occurs in the real-world setting. <p>Finally, we evaluated our design in a simulated digital-tabletop task with the goal of assessing the usefulness of various digital transfer techniques including standard deposit, traditional handoff, force-field and 3D-handoff. The results showed that on the digital tabletop system the percentage of using deposit, 2D-handoff and 3D-handoff techniques is similar with the percentage of using these techniques on the real world physical table. 3D-handoff was the most preferred and the most frequently used technique among the handoff techniques; and the force-field technique is preferred than traditional handoff technique.

In the field of digital media, the study of interactive narratives holds the aesthetics of agency and dramatic agency as core to digital design. These principles hold that users must reliably be able to navigate the interface and the narrative elements of the artifact in order to have a lasting appeal. However, due to recent academic and critical discussions several digital artifacts are being focused on as possible new ways of engaging users. These artifacts do not adhere to the design aesthetics foundational to digital media, but represent a movement away from the principle of dramatic agency in interactive narratives. In an attempt to understand this separation and offer a solution to this developing issue, another non-digital interactive medium was studied: tabletop role-playing games. The designers of this medium were studied to understand the techniques and methods they employed to create dramatic interactive narratives for their users. These case studies suggested the designers used a third design aesthetic, design agency, to help balance the tension between agency and dramatic agency of the users of their medium. This design aesthetic could provide a balancing force to the current issues arising within interactive narrative.

Doctor of Philosophy(PhD) / Digital photography has not only changed the nature of photography and the photographic process, but also the manner in which we share photographs and tell stories about them. Some traditional methods, such as the family photo album or passing around piles of recently developed snapshots, are lost to us without requiring the digital photos to be printed. The current, purely digital, methods of sharing do not provide the same experience as printed photographs, and they do not provide effective face-to-face social interaction around photographs, as experienced during storytelling. Research has found that people are often dissatisfied with sharing photographs in digital form. The recent emergence of the tabletop interface as a viable multi-user direct-touch interactive large horizontal display has provided the hardware that has the potential to improve our collocated activities such as digital photograph sharing. However, while some software to communicate with various tabletop hardware technologies exists, software aspects of tabletop user interfaces are still at an early stage and require careful consideration in order to provide an effective, multi-user immersive interface that arbitrates the social interaction between users, without the necessary computer-human interaction interfering with the social dialogue. This thesis presents PhoTable, a social interface allowing people to effectively share, and tell stories about, recently taken, unsorted digital photographs around an interactive tabletop. In addition, the computer-arbitrated digital interaction allows PhoTable to capture the stories told, and associate them as audio metadata to the appropriate photographs. By leveraging the tabletop interface and providing a highly usable and natural interaction we can enable users to become immersed in their social interaction, telling stories about their photographs, and allow the computer interaction to occur as a side-effect of the social interaction. Correlating the computer interaction with the corresponding audio allows PhoTable to annotate an automatically created digital photo album with audible stories, which may then be archived. These stories remain useful for future sharing -- both collocated sharing and remote (e.g. via the Internet) -- and also provide a personal memento both of the event depicted in the photograph (e.g. as a reminder) and of the enjoyable photo sharing experience at the tabletop. To provide the necessary software to realise an interface such as PhoTable, this thesis explored the development of Cruiser: an efficient, extensible and reusable software framework for developing tabletop applications. Cruiser contributes a set of programming libraries and the necessary application framework to facilitate the rapid and highly flexible development of new tabletop applications. It uses a plugin architecture that encourages code reuse, stability and easy experimentation, and leverages the dedicated computer graphics hardware and multi-core processors of modern consumer-level systems to provide a responsive and immersive interactive tabletop user interface that is agnostic to the tabletop hardware and operating platform, using efficient, native cross-platform code. Cruiser's flexibility has allowed a variety of novel interactive tabletop applications to be explored by other researchers using the framework, in addition to PhoTable. To evaluate Cruiser and PhoTable, this thesis follows recommended practices for systems evaluation. The design rationale is framed within the above scenario and vision which we explore further, and the resulting design is critically analysed based on user studies, heuristic evaluation and a reflection on how it evolved over time. The effectiveness of Cruiser was evaluated in terms of its ability to realise PhoTable, use of it by others to explore many new tabletop applications, and an analysis of performance and resource usage. Usability, learnability and effectiveness of PhoTable was assessed on three levels: careful usability evaluations of elements of the interface; informal observations of usability when Cruiser was available to the public in several exhibitions and demonstrations; and a final evaluation of PhoTable in use for storytelling, where this had the side effect of creating a digital photo album, consisting of the photographs users interacted with on the table and associated audio annotations which PhoTable automatically extracted from the interaction. We conclude that our approach to design has resulted in an effective framework for creating new tabletop interfaces. The parallel goal of exploring the potential for tabletop interaction as a new way to share digital photographs was realised in PhoTable. It is able to support the envisaged goal of an effective interface for telling stories about one's photos. As a serendipitous side-effect, PhoTable was effective in the automatic capture of the stories about individual photographs for future reminiscence and sharing. This work provides foundations for future work in creating new ways to interact at a tabletop and to the ways to capture personal stories around digital photographs for sharing and long-term preservation.

With augmented reality, we can create interfaces that merge virtual objects and data seamlessly with the real world, potentially improving collaboration and interaction. This technology offers opportunities for games, allowing new designs that merge the diverse social and physical interaction of real world games with rapid interactivity and computing power of digital games. To date, research has primarily focused on issues of technology, interaction design, and nfrastructure; the design of compelling play has received little attention. We play games because they are enjoyable; therefore, in order to create attractive games, we must understand enjoyment. In games, engagement, social interaction, and emotional involvement are among the most common causes. We can design for engagement in play using Csikszentmihalyi's model of 'flow'; for social play by making communication easy, natural, and useful; and emotional involvement by understanding the mechanisms by which games stimulate us. Alongside an understanding of enjoyment, lessons must be drawn from design experience. AR Tankwar is an augmented reality strategy game developed over the course of this thesis, and has been evaluated in the field at a large games convention, and in a detailed comparative study with existing games on tabletop and desktop PC. Evaluations revealed predictable limitations with the technology, but also provided insight into how designers can make best use of the medium. Based on these activities, and existing knowledge of interaction and collaboration in augmented reality, this thesis addresses compelling play in augmented reality by developing a set of design guidelines for augmented reality games, with particular focus on strategy games.

Doctor of Philosophy(PhD) / Digital photography has not only changed the nature of photography and the photographic process, but also the manner in which we share photographs and tell stories about them. Some traditional methods, such as the family photo album or passing around piles of recently developed snapshots, are lost to us without requiring the digital photos to be printed. The current, purely digital, methods of sharing do not provide the same experience as printed photographs, and they do not provide effective face-to-face social interaction around photographs, as experienced during storytelling. Research has found that people are often dissatisfied with sharing photographs in digital form. The recent emergence of the tabletop interface as a viable multi-user direct-touch interactive large horizontal display has provided the hardware that has the potential to improve our collocated activities such as digital photograph sharing. However, while some software to communicate with various tabletop hardware technologies exists, software aspects of tabletop user interfaces are still at an early stage and require careful consideration in order to provide an effective, multi-user immersive interface that arbitrates the social interaction between users, without the necessary computer-human interaction interfering with the social dialogue. This thesis presents PhoTable, a social interface allowing people to effectively share, and tell stories about, recently taken, unsorted digital photographs around an interactive tabletop. In addition, the computer-arbitrated digital interaction allows PhoTable to capture the stories told, and associate them as audio metadata to the appropriate photographs. By leveraging the tabletop interface and providing a highly usable and natural interaction we can enable users to become immersed in their social interaction, telling stories about their photographs, and allow the computer interaction to occur as a side-effect of the social interaction. Correlating the computer interaction with the corresponding audio allows PhoTable to annotate an automatically created digital photo album with audible stories, which may then be archived. These stories remain useful for future sharing -- both collocated sharing and remote (e.g. via the Internet) -- and also provide a personal memento both of the event depicted in the photograph (e.g. as a reminder) and of the enjoyable photo sharing experience at the tabletop. To provide the necessary software to realise an interface such as PhoTable, this thesis explored the development of Cruiser: an efficient, extensible and reusable software framework for developing tabletop applications. Cruiser contributes a set of programming libraries and the necessary application framework to facilitate the rapid and highly flexible development of new tabletop applications. It uses a plugin architecture that encourages code reuse, stability and easy experimentation, and leverages the dedicated computer graphics hardware and multi-core processors of modern consumer-level systems to provide a responsive and immersive interactive tabletop user interface that is agnostic to the tabletop hardware and operating platform, using efficient, native cross-platform code. Cruiser's flexibility has allowed a variety of novel interactive tabletop applications to be explored by other researchers using the framework, in addition to PhoTable. To evaluate Cruiser and PhoTable, this thesis follows recommended practices for systems evaluation. The design rationale is framed within the above scenario and vision which we explore further, and the resulting design is critically analysed based on user studies, heuristic evaluation and a reflection on how it evolved over time. The effectiveness of Cruiser was evaluated in terms of its ability to realise PhoTable, use of it by others to explore many new tabletop applications, and an analysis of performance and resource usage. Usability, learnability and effectiveness of PhoTable was assessed on three levels: careful usability evaluations of elements of the interface; informal observations of usability when Cruiser was available to the public in several exhibitions and demonstrations; and a final evaluation of PhoTable in use for storytelling, where this had the side effect of creating a digital photo album, consisting of the photographs users interacted with on the table and associated audio annotations which PhoTable automatically extracted from the interaction. We conclude that our approach to design has resulted in an effective framework for creating new tabletop interfaces. The parallel goal of exploring the potential for tabletop interaction as a new way to share digital photographs was realised in PhoTable. It is able to support the envisaged goal of an effective interface for telling stories about one's photos. As a serendipitous side-effect, PhoTable was effective in the automatic capture of the stories about individual photographs for future reminiscence and sharing. This work provides foundations for future work in creating new ways to interact at a tabletop and to the ways to capture personal stories around digital photographs for sharing and long-term preservation.

Fantasy play is when children explore and travel through time and space, to interpret experiences into stories and to act them out. Children love this kind of play and it is really important for developing skills which will be used later in life. Today, computers are increasingly present in children's lives, and the development of technology over recent decades has changed the way children play. This thesis explores the possibility of young children (aged 3-4) enacting their fantasy play in a virtual environment. Three different games were designed and implemented on a Mitsubishi DiamondTouch (DT) multi-touch interactive tabletop. Three evaluation studies were conducted and the performance of the children's fantasy play was examined. In each study, children were recruited from a local preschool class. The first study was designed to compare fantasy play in physical and virtual settings. Children from the preschool class in a state primary school were invited to play with both a real tree house and its virtual implementation on a Mitsubishi DiamondTouch (DT) multi-touch interactive tabletop. Overall, the children played quietly and alone. The results evinced several problems in the interaction with the tabletop as children struggled to drag the objects displayed on the table surface. Therefore, the study did not provide conclusive evidence of a distinction in fantasy in physical and virtual environments. The second study was concentrated on testing solutions for the interaction difficulties evinced in the first study. A new application named The Magic House was developed and implemented on a Mitsubishi DT multi-touch interactive tabletop and tested twice with the preschool children. The results showed that most of the interaction problems from Study 1 were eliminated; evidence of more fantasy play was captured, and children played more confidently in the second evaluation session. The third study was designed to investigate and to compare children's fantasy play in physical and virtual settings. A new physical setting and the virtual implementation on the Mitsubishi DT multi-touch interactive tabletop of materials named The Farm were designed and examined with a group of preschool children. The results revealed that high occurrence of fantasy play was observed in the virtual setting and several similarities and dissimilarities between the two settings was also highlighted. Overall, this thesis produced knowledge on how the application on the multi-touch interactive tabletop environment was designed and evaluated with preschool children. The thesis results demonstrate that appropriate interaction design of virtual environments could stimulate preschool children's fantasy play and the tabletop can be operated by children as young as three. This thesis also specified requirements for designing and facilitating tabletop environments for preschool children's fantasy play.

Protection of personal information has become a critical issue in the digital world. Many companies and service provider websites have adopted privacy policies and practices to protect users’ personal information to some extent. In addition, various governments are adopting privacy protection legislation. System developers, service providers, and interface designers play an important role in determining how to make systems fulfill legal requirements and satisfy users. The human factor requirements for effective privacy interface design can be categorized into four groups: (1) comprehension, (2) consciousness, (3) control, and (4) consent (Patrick & Kenny, 2003). Moreover, the type of technology that people are engaged with has a crucial role in determining what type of practices should be adopted. As Weiser (1996) envisioned, we are now in an “ubiquitous computing” (Ubicomp) era in which technologies such as digital tabletops (what Weiser called LiveBoards) are emerging for use in public settings. The collaborative and open nature of this type of smart device introduces new privacy threats that have not yet been thoroughly investigated and as a result have not been addressed in companies’ and governmental privacy statements and legislation. In this thesis, I provide an analytical description of the privacy threats unique to tabletop display environments. I then present several design suggestions for a tabletop display interface that addresses and mitigates these threats, followed by a qualitative evaluation of these designs based on Patrick and Kenny’s (2003) model. Results show that most participants have often experienced being shoulder-surfed or had privacy issues when sharing information with someone in a collaborative environment. Therefore, they found most of the techniques designed in this thesis helpful in providing information privacy for them when they are engaged with online social activities on digital tabletops in public settings. Among all of the proposed tested designs, the first three have proven to be effective in providing the required privacy. However, designs 4 and 5 had some shortfalls that made them less helpful for participants. The main problem with these two designs was that participants had difficulty understanding what they had to do in order to complete the given tasks.

Interactive tabletop systems are becoming popular platforms for group activities. However, current common tabletops do not provide capabilities to differentiate interactions among simultaneous users, i.e. to associate a touch point with its proper owner. My thesis proposes and explores the use of an important biometric property of users as the basis for touch discrimination on multi-user tabletops: Finger Orientation (FO). In this thesis, I first collect the FO ranges of users standing in different positions around a tabletop. Second, I implement a system that uses FO to determine where the users are standing, and based on that extrapolate the owner of the touch. Next, I evaluate the system with two separate experiments, present the results, and discuss all findings. Furthermore, I explore some enhancements with a simple quantitative study. My results indicate that finger orientation is a good natural biometric trait enhances multi-user recognition on tabletops.

This project report describes a supplement for character creation in a tabletop role-playing game “Dragons and Demons." The purpose of this project is to improve the character creation for the players’ trough the narrative elements such as character’s background story. The applied qualitative methods such as a test panel and a questionnaire were conducted for the evaluation of theories used during character creation and to get feedback on the supplement’s creative value for the players. The aim of the questionnaire was to see how the method for the character creation differs from the regular way of making a character for a tabletop role-playing game and if this idea improves user experience during the tabletop role-playing game. The results of the evaluation are based on answers from novice and experienced players, and conclude that the additional background story creates an insight into the character's past, which makes it easier for novice players to get quick started with character creation. The experienced players expressed that the supplement for character creation was more entertaining than the traditional way of making a character for a tabletop role-playing game.