Jennifer Mankoff

Heuristic evaluation of ambient displays

We present a technique for evaluating the usability and effectiveness of ambient displays. Ambient displays are abstract and aesthetic peripheral displays portraying non-critical information on the periphery of a users attention. Although many innovative displays have been published, little existing work has focused on their evaluation, in part because evaluation of ambient displays is difficult and costly. We adapted a low-cost evaluation technique, heuristic evaluation, for use with ambient displays. With the help of ambient display designers, we defined a modified set of heuristics. We compared the performance of Nielsens heuristics and our heuristics on two ambient displays. Evaluators using our heuristics found more, severe problems than evaluators using Nielsens heuristics. Additionally, when using our heuristics, 3-5 evaluators were able to identify 40--60% of known usability issues. This implies that heuristic evaluation is an effective technique for identifying usability issues with ambient displays.

Who wants to know what when? privacy preference determinants in ubiquitous computing

We conducted a questionnaire-based study of the relative importance of two factors, inquirer and situation, in determining the preferred accuracy of personal information disclosed through a ubiquitous computing system. We found that privacy preferences varied by inquirer more than by situation. That is, individuals were more likely to apply the same privacy preferences to the same inquirer in different situations than to apply the same privacy preferences to different inquirers in the same situation. We are applying these results to the design of a user interface for managing everyday privacy in ubiquitous computing.

A toolkit for managing user attention in peripheral displays

Traditionally, computer interfaces have been confined to conventional displays and focused activities. However, as displays become embedded throughout our environment and daily lives, increasing numbers of them must operate on the periphery of our attention. <i>Peripheral displays</i> can allow a person to be aware of information while she is attending to some other primary task or activity. We present the Peripheral Displays Toolkit (PTK), a toolkit that provides structured support for managing user attention in the development of peripheral displays. Our goal is to enable designers to explore different approaches to managing user attention. The PTK supports three issues specific to conveying information on the periphery of human attention. These issues are <i>abstraction</i> of raw input, rules for assigning <i>notification levels</i> to input, and <i>transitions</i> for updating a display when input arrives. Our contribution is the investigation of issues specific to attention in peripheral display design and a toolkit that encapsulates support for these issues. We describe our toolkit architecture and present five sample peripheral displays demonstrating our toolkits capabilities.

Distributed mediation of ambiguous context in aware environments

Many context-aware services make the assumption that the context they use is completely accurate. However, in reality, both sensed and interpreted context is often ambiguous. A challenge facing the development of realistic and deployable context-aware services, therefore, is the ability to handle ambiguous context. In this paper, we describe an architecture that supports the building of context-aware services that assume context is ambiguous and allows for mediation of ambiguity by mobile users in aware environments. We illustrate the use of our architecture and evaluate it through three example context-aware services, a word predictor system, an In/Out Board, and a reminder tool.

Using Low-Cost Sensing to Support Nutritional Awareness

Nutrition has a big impact on health, including major diseases such as heart disease, osteoporosis, and cancer. This paper presents an application designed to help people keep track of the nutrional content of foods they have eaten. Our work uses shopping receipts to generate suggestions about healthier food items that could help to supplement missing nutrients. We present our system design: a capture and access application that, based on shopping receipt data, provides access to ambiguous suggestions for more nutritious purchases. We also report results from one formative user study suggesting that receipts may provide enough information to extend our work by also estimating what people are actually eating, as opposed to simply what they are purchasing.

Can you see what i hear?: the design and evaluation of a peripheral sound display for the deaf

We developed two visual displays for providing awareness of environmental audio to deaf individuals. Based on fieldwork with deaf and hearing participants, we focused on supporting awareness of non-speech audio sounds such as ringing phones and knocking in a work environment. Unlike past work, our designs support both monitoring and notification of sounds, support discovery of new sounds, and do not require a priori knowledge of sounds to be detected. Our Spectrograph design shows pitch and amplitude, while our Positional Ripples design shows amplitude and location of sounds. A controlled experiment involving deaf participants found neither display to be significantly distracting. However, users preferred the Positional Ripples display and found that display easier to monitor (notification sounds were detected with 90% success in a laboratory setting). The Spectrograph display also supported successful detection in most cases, and was well received when deployed in the field.

Web accessibility for low bandwidth input

One of the first, most common, and most useful applications that todays computer users access is the World Wide Web (web). One population of users for whom the web is especially important is those with motor disabilities, because it may enable them to do things that they might not otherwise be able to do: shopping; getting an education; running a business. This is particularly important for low bandwidth users: users with such limited motor and speech that they can only produce one or two signals when communicating with a computer. We present requirements for low bandwidth web accessibility, and two tools that address these requirements. The first is a modified web browser, the second a proxy that modifies HTML. Both work without requiring web page authors to modify their pages.

Building Connections among Loosely Coupled Groups: Hebb's Rule at Work

Awareness of others’ interests can lead to fruitful collaborations, friendships and positive social change. Interviews of groups involved in both research and corporate work revealed a lack of awareness of shared interests among workers sharing an organizational affiliation and collocated in the same building or complex but still physically separated (e.g., by walls or floors). Our study showed that loosely coupled groups were less likely to discover shared interests in the way that many tightly collocated groups do, such as by overhearing conversations or noticing paraphernalia. Based on these findings we iteratively developed a system to capture and display shared interests. Our platform includes an e-mail sensor to discover personal interests, a search algorithm to determine shared interests, a public peripheral display and lightweight location-tracking system to convey those interests. We deployed the system to two groups for two months and found that the system did lead to increased awareness of shared interests.

Theoretical and architectural support for input device adaptation

The graphical user interface (GUI) is todays de facto standard for desktop computing. GUIs are designed and optimized for use with a mouse and keyboard. However, modern trends make this reliance on a mouse and keyboard problematic for two reasons. First, people with disabilities may have trouble operating those devices. Second, with the popularization of wireless communication and mobile devices such as personal data assistants, the mouse and keyboard are often replaced by other input devices. Our solution is a tool that can be used to translate a users input to a form recognizable by any Windows-based application. We argue that a formal model of input is necessary to support arbitrary translations of this sort. We present a model, based on Markov information sources, that extends past work in its ability to handle software-based input such as speech recognition, and to measure relative device bandwidth. We also present our translation tool, which is based on our model, along with four applications built using that tool.

From Conception to Design

This chapter discusses displays that sit on the periphery of a user’s attention. Many public displays of information that we encounter are in this category the majority of the time, including clocks, posters, and windows. Computationally enhanced variations on this theme are called peripheral displays. Our work focuses on ambient displays, a subset of peripheral displays that continuously display information to be monitored. Peripheral (and ambient) displays have the peculiar property that they are not meant to be the focus of the user’s attention. Contrast this with desktop applications, which require a user’s attention. In this chapter, we present a case study of two public ambient displays that we developed and evaluated. We present some lessons learned about the design of ambient displays, and conclude with a practical guide to using a modified version of heuristic evaluation that we developed as a result of designing these displays.