Jonathan Hook

Multi-touch authentication on tabletops

The introduction of tabletop interfaces has given rise to the need for the development of secure and usable authentication techniques that are appropriate for the co-located collaborative settings for which they have been designed. Most commonly, user authentication is based on something you know, but this is a particular problem for tabletop interfaces, as they are particularly vulnerable to shoulder surfing given their remit to foster co-located collaboration. In other words, tabletop users would typically authenticate in full view of a number of observers. In this paper, we introduce and evaluate a number of novel tabletop authentication schemes that exploit the features of multi-touch interaction in order to inhibit shoulder surfing. In our pilot work with users, and in our formal user-evaluation, one authentication scheme - Pressure-Grid - stood out, significantly enhancing shoulder surfing resistance when participants used it to enter both PINs and graphical passwords.

A reconfigurable ferromagnetic input device

We present a novel hardware device based on ferromagnetic sensing, capable of detecting the presence, position and deformation of any ferrous object placed on or near its surface. These objects can include ball bearings, magnets, iron filings, and soft malleable bladders filled with ferrofluid. Our technology can be used to build reconfigurable input devices -- where the physical form of the input device can be assembled using combinations of such ferrous objects. This allows users to rapidly construct new forms of input device, such as a trackball-style device based on a single large ball bearing, tangible mixers based on a collection of sliders and buttons with ferrous components, and multi-touch malleable surfaces using a ferrofluid bladder. We discuss the implementation of our technology, its strengths and limitations, and potential application scenarios.

A VJ centered exploration of expressive interaction

This paper identifies key themes of expressive interaction for VJs. VJs are visual artists who use digital media to express themselves to an audience during a live audio-visual performance. Those designing for the expressive use of technology can gain insight from an articulation of expressive interaction from the perspective of VJ practice. This is developed using a novel qualitative methodology designed to be sensitive to the subtle and tacit nature of expression. We detail our methodology, present the results of its application to a group of VJs and conclude with a discussion of the implications our findings may have for those wishing to design for VJs, or those in related domains that involve expressive interaction with technology.

A study of the challenges related to DIY assistive technology in the context of children with disabilities

The term Do It Yourself Assistive Technology (DIY-AT) refers to the creation and adaptation of AT by non-professionals, including people with disabilities and their families, friends and caregivers. Previous research has argued that the development of technologies and services that enable people to make their own DIY-AT will lead to the rapid and low cost development of assistive devices that are tailored to meet the complex needs of individual people with disabilities. We present the results of a qualitative study that explored challenges related to the process of making DIY-AT for children with disabilities. A series of eleven semi-structured interviews with a broad range of stakeholders involved in the current use, provision and adaptation of AT for children with disabilities revealed a number of challenges relating to the prevalence and scope of ongoing DIY-AT practice, barriers to participation, and the challenges faced by makers and users of DIY-AT.

Group coordination and negotiation through spatial proximity regions around mobile devices on augmented tabletops

Negotiation and coordination of activities involving a number of people can be a difficult and time-consuming process, even when all participants are collocated. We propose the use of spatial proximity regions around mobile devices on a table to significantly reduce the effort of proposing and exploring content within a group of collocated people. In order to determine the location of devices on ordinary tables, we developed a tracking mechanism for a camera-projector system that uses dynamic visual markers displayed on the screen of a device. We evaluated our spatial proximity region based approach using a photo-sharing application for people sat around a table. The tabletop provides a frame of reference in which the spatial arrangement of devices signals the coordination state to the users. The results from the study indicate that the proposed approach facilitates coordination in several ways, for example, by allowing for simultaneous user activity and by reducing the effort required to achieve a common goal. Our approach reduced the task completion time by 43% and was rated as superior in comparison to other established techniques.

Expressy: Using a Wrist-worn Inertial Measurement Unit to Add Expressiveness to Touch-based Interactions

Expressiveness, which we define as the extent to which rich and complex intent can be conveyed through action, is a vital aspect of many human interactions. For instance, paint on canvas is said to be an expressive medium, because it affords the artist the ability to convey multifaceted emotional intent through intricate manipulations of a brush. To date, touch devices have failed to offer users a level of expressiveness in their interactions that rivals that experienced by the painter and those completing other skilled physical tasks. We investigate how data about hand movement -- provided by a motion sensor, similar to those found in many smart watches or fitness trackers -- can be used to expand the expressiveness of touch interactions. We begin by introducing a conceptual model that formalizes a design space of possible expressive touch interactions. We then describe and evaluate Expressy, an approach that uses a wrist-worn inertial measurement unit to detect and classify qualities of touch interaction that extend beyond those offered by todays typical sensing hardware. We conclude by describing a number of sample applications, which demonstrate the enhanced, expressive interaction capabilities made possible by Expressy.

Making 3D printed objects interactive using wireless accelerometers

We present an approach that allows designers and others to quickly and easily make 3D printed objects interactive, without the need for hardware or software expertise and with little modification to an objects physical design. With our approach, a designer simply attaches or embeds small three-axis wireless accelerometer modules into the moving parts of a 3D printed object. A simple graphical user interface is then used to configure the system to interpret the movements of these accelerometers as if they were common physical controls such as buttons or dials. The designer can then associate events generated by these controls with a range of interactive behavior, including web browser and media player control.

Exploring HCI's relationship with liveness

Liveness has long been a valued quality of mass media presentation in areas such as music, sports and debate. The rapid development of new digital media, and the interpenetration of these media and staged performance, places liveness center stage in attempts to understand emerging human-computer configurations. This workshop will bring together insights from a variety of disciplines and perspectives to explore how HCI can benefit from critical engagement with theoretical and practical treatment of liveness. To seed discussion and action, participants will engage reflectively with the liveness of an authentic performance, experienced firsthand and at one-remove through a mediating technology, using an innovative video-based methodology.

Making the Invisible Visible: Design to Support the Documentation of Participatory Arts Experiences

We explore how digital technology might support the documentation of experiences of participatory arts engagement. During a fourteen session workshop series, we worked with artists, project managers, support workers and participants to explore the integration of digital media capture and presentation technologies into participatory arts workshops, and the implications that this would have for the experiences and practices of key stakeholders involved. We contribute insight into the social and practical challenges faced when using digital technology to create documentation of participatory arts. Our findings highlight the importance of situating documentation, sense making and re-telling of experiences in sensitive contexts such as participatory arts within the practices of skilled interpreters that are mindful of the complexities involved.

Design to support interpersonal communication in the special educational needs classroom

This paper describes our Experience-centered Design (ECD) inquiry into the current and potential role of digital photography to support interpersonal communication and expression in a class at a mixed special education needs school. Presented as a case study, we describe five classroom-based Creative Photography workshops that engaged pupils with a broad range of complex special needs, along with classroom staff. We further describe how, from these workshops, we generated a set of qualitative considerations for the design of digital photographic tools to support interpersonal communication and expression in this setting. Additionally, we present the preliminary evaluation of a photo-sorting tool that we developed in response. Our case study demonstrates how an ECD approach can guide an interaction design process in a special education needs setting, supporting interaction designers in understanding and responding pragmatically to the complex and dynamic interactions at play between the stakeholders.