Katherine Everitt

Design requirements for technologies that encourage physical activity

Overweight and obesity are a global epidemic, with over one billion overweight adults worldwide (300+ million of whom are obese). Obesity is linked to several serious health problems and medical conditions. Medical experts agree that physical activity is critical to maintaining fitness, reducing weight, and improving health, yet many people have difficulty increasing and maintaining physical activity in everyday life. Clinical studies have shown that health benefits can occur from simply increasing the number of steps one takes each day and that social support can motivate people to stay active. In this paper, we describe Houston, a prototype mobile phone application for encouraging activity by sharing step count with friends. We also present four design requirements for technologies that encourage physical activity that we derived from a three-week long in situ pilot study that was conducted with women who wanted to increase their physical activity.

UbiTable: Impromptu Face-to-Face Collaboration on Horizontal Interactive Surfaces

Despite the mobility enabled by the plethora of technological tools such as laptops, PDA and cell phones, horizontal flat surfaces are still extensively used and much preferred for on-the-move face-to-face collaboration. Unfortunately, when digital documents need to be shared during collaboration, people are still mostly constrained to display surfaces that have been designed for single users, such as laptops and PDAs. Technologically there is a lack of computational support for shared digital document access, browsing, visualization and manipulation on horizontal surfaces. We believe support for such serendipitous meetings will play a critical role in future ubiquitous computing spaces. Our UbiTable project examines the design space of tabletops used as scrap displays. Scrap displays support kiosk-style walk-up interaction for impromptu face-to-face collaboration. Our design offers the affordances of a physical table. It provides the flexibility by allowing users to layout shared documents with desired orientation and position; at the same time it augments traditional paper-based interactions by providing a flexible gradient or shades of sharing semantics. UbiTable addresses visual accessibility vs. electronic accessibility of documents, an issue which is critical to ubiquitous environments.

A comprehensive study of frequency, interference, and training of multiple graphical passwords

Graphical password systems have received significant attention as one potential solution to the need for more usable authentication, but nearly all prior work makes the unrealistic assumption of studying a single password. This paper presents the first study of multiple graphical passwords to systematically examine frequency of access to a graphical password, interference resulting from interleaving access to multiple graphical passwords, and patterns of access while training multiple graphical passwords. We find that all of these factors significantly impact the ease of authenticating using multiple facial graphical passwords. For example, participants who accessed four different graphical passwords per week were ten times more likely to completely fail to authenticate than participants who accessed a single password once per week. Our results underscore the need for more realistic evaluations of the use of multiple graphical passwords, have a number of implications for the adoption of graphical password systems, and provide a new basis for comparing proposed graphical password systems.

Predictability and accuracy in adaptive user interfaces

While proponents of adaptive user interfaces tout potential performance gains, critics argue that adaptations unpredictability may disorient users, causing more harm than good. We present a study that examines the relative effects of predictability and accuracy on the usability of adaptive UIs. Our results show that increasing predictability and accuracy led to strongly improved satisfaction. Increasing accuracy also resulted in improved performance and higher utilization of the adaptive interface. Contrary to our expectations, improvement in accuracy had a stronger effect on performance, utilization and some satisfaction ratings than the improvement in predictability.

iDwidgets: parameterizing widgets by user identity

We introduce the concept of identity-differentiating widgets (iDwidgets), widgets parameterized by the identity of their user. Although multi-user applications have become more common, most support only traditional “single-user” widgets. By adding user-identity information we allow interactions with today’s widgets to be dynamically customized on a per-user basis in a group usage setting. The concept has inspired the design of new widgets as well. In this paper we describe example iDwidgets and define a conceptual framework based on what is being customized in the widget. iDwidgets can support novel interaction techniques in collaborative settings.

DocuDesk: An interactive surface for creating and rehydrating many-to-many linkages among paper and digital documents

Knowledge workers often undertake tasks that involve a variety of information artifacts, including both paper and digital documents. In this paper, we first summarize findings from a study that illustrate some of the challenges of managing tasks that include both paper and digital content. We then introduce DocuDesk, a prototype interactive desk that demonstrates interaction techniques for establishing many-to-many linkages among paper and digital documents which can be used to quickly ldquorehydraterdquo task state.

Identity-Differentiating Widgets for Multiuser Interactive Surfaces

Widgets - standard reusable GUI elements - are a staple of user-interface development. The use of widget toolkits, such as Javas Swing, X Window Systems Motif, or Microsofts MFC, allows programmers to quickly incorporate a number of standard interactions (such as clicking buttons, selecting check boxes, or scrolling through lists) into their software. To date, most widgets have been designed for use by one person at a time. Within a single session, a widget behaves the same regardless of who uses it. By applying the iDwidgets concept, the authors supplement traditional widgets with identity differentiation that supports widget reuse, dynamic widget customization, clutter reduction, and novel multiuser widget type creation. This article introduces a conceptual framework for iDwidgets, describing four axes that application can customize by exploiting identity differentiation: function, content, appearance, and group input

Collaborative Tabletop Research and Evaluation

Tables provide a large and natural interface for supporting direct manipulation of visual content, for human-to-human interactions and for collaboration, coordination, and parallel problem solving. However, the direct-touch table metaphor also presents considerable challenges, including the need for input methods that transcend traditional mouse- and keyboard-based designs.

Disambiguating speech commands using physical context

Speech has great potential as an input mechanism for ubiquitous computing. However, the current requirements necessary for accurate speech recognition, such as a quiet environment and a well-positioned and high-quality microphone, are unreasonable to expect in a realistic setting. In a physical environment, there is often contextual information which can be sensed and used to augment the speech signal. We investigated improving speech recognition rates for an electronic personal trainer using knowledge about what equipment was in use as context. We performed an experiment with participants speaking in an instrumented apartment environment and compared the recognition rates of a larger grammar with those of a smaller grammar that is determined by the context.

DocuBits and containers: providing e-document micro-mobility in a walk-up interactive tabletop environment

A key challenge in supporting face-to-face collaborative work is edocument micro-mobility: supporting movement of digital content amongst shared display surfaces and personal devices at arbitrary levels of document granularity. Micro-mobility is a dexterity that physical paper artifacts afford – the ability to be handled with any position and placement, to be dismantled, cut and torn apart, marked up, reassembled and sorted. To support micromobility for electronic content and group work, we propose DocuBits and Containers. DocuBits offer the metaphor of a paper-cutter and a scanner for electronic documents. A portion of screen ‘bits’ from any application or any parts of visible display can be cut, grabbed, sent and launched onto a different display surface or device with minimal interaction – merely three mouse/stylus click-select. Once arrived on the target display surface, DocuBits can be arbitrarily positioned, re-oriented, marked up, and pulled into other documents, or again sent to other display surfaces. A Container is a composite draft of DocuBits and other documents, usually composed as the outcome of a collaborative meeting.