Gary Hsieh

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.

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.

User-Controllable Security and Privacy for Pervasive Computing

We describe our current work in developing novel mechanisms for managing security and privacy in pervasive computing environments. More specifically, we have developed and evaluated three different applications, including a contextual instant messenger, a people finder application, and a phone-based application for access control. We also draw out some themes we have learned thus far for user-controllable security and privacy.

Unlocking the expressivity of point lights

Small point lights (e.g., LEDs) are used as indicators in a wide variety of devices today, from digital watches and toasters, to washing machines and desktop computers. Although exceedingly simple in their output - varying light intensity over time - their design space can be rich. Unfortunately, a survey of contemporary uses revealed that the vocabulary of lighting expression in popular use today is small, fairly unimaginative, and generally ambiguous in meaning. In this paper, we work through a structured design process that points the way towards a much richer set of expressive forms and more effective communication for this very simple medium. In this process, we make use of five different data gathering and evaluation components to leverage the knowledge, opinions and expertise of people outside our team. Our work starts by considering what information is typically conveyed in this medium. We go on to consider potential expressive forms -- how information might be conveyed. We iteratively refine and expand these sets, concluding with ideas gathered from a panel of designers. Our final step was to make use of thousands of human judgments, gathered in a crowd-sourced fashion (265 participants), to measure the suitability of different expressive forms for conveying different information content. This results in a set of recommended light behaviors that mobile devices, such as smartphones, could readily employ.

mimir: a market-based real-time question and answer service

Community-based question and answer (Q&A) systems facilitate information exchange and enable the creation of reusable knowledge repositories. While these systems are growing in usage and are changing how people find and share information, current designs are inefficient, wasting the time and attention of their users. Furthermore, existing systems do not support signaling and screening of joking and non-serious questions. Coupling Q&A services with instant and text messaging for faster questions and answers may exacerbate these issues, causing Q&A services to incur high interruption costs on their users. In this paper we present the design and evaluation of a market-based real-time Q&A system. We compared its use to a similar Q&A system without a market. We found that while markets can reduce wasted resources by reducing the number of less important questions and low quality answers, it may also reduce the socially conducive questions and usages that are vital to sustaining a Q&A community.

Field deployment of IMBuddy: a study of privacy control and feedback mechanisms for contextual IM

We describe the design of privacy controls and feedback mechanisms for contextual IM, an instant messaging service for disclosing contextual information. We tested our designs on IMBuddy, a contextual IM service we developed that discloses contextual information, including interruptibility, location, and the current window in focus (a proxy for the current task). We deployed our initial design of IMBuddys privacy mechanisms for two weeks with ten IM users. We then evaluated a redesigned version for four weeks with fifteen users. Our evaluation indicated that users found our group-level rule-based privacy control intuitive and easy to use. Furthermore, the set of feedback mechanisms provided users with a good awareness of what was disclosed.

The influence of competition, cooperation, and player relationship in a motor performance centered computer game

We conducted an experiment to study the effects of goal structure in multiplayer gaming (competition vs. cooperation) and relationship type between players (positive pre-existing relationship [friends] vs. no pre-existing relationship [strangers]) on player motivation (as indicated by perceived effort put into the task), goal commitment, and performance in playing a balloon popping game. The cooperative goal structure was found to lead to greater effort put into the game than the competitive goal structure. In addition, playing with friends resulted in a stronger commitment to the in-game goals than playing with strangers in the cooperative goal structure context, yet no difference was found between playing with friends and playing with strangers with regard to goal commitment in the competitive goal structure context. A moderated mediation relationship was found among the variables. Theoretical contributions to the current literature on goal structure and motivation, practical implications for exergame design, and directions for future research are discussed.

Understanding individuals' personal values from social media word use

The theory of values posits that each person has a set of values, or desirable and trans-situational goals, that motivate their actions. The Basic Human Values, a motivational construct that captures peoples values, have been shown to influence a wide range of human behaviors. In this work, we analyze peoples values and their word use on Reddit, an online social news sharing community. Through conducting surveys and analyzing text contributions of 799 Reddit users, we identify and interpret categories of words that are indicative of users value orientations. Using the same data, we further report a preliminary exploration on word-based prediction of Basic Human Values.

DanceAlong: supporting positive social exchange and exercise for the elderly through dance

The elderly face serious social, environmental, and physical constraints that impact their well-being. Some of the most serious of these are shrinking social connections, limitations in building new relationships, and diminished health. To address these issues, we have designed an augmented dancing environment that allows elders to select dance sequences from well-known movies and dance along with them. The goal of DanceAlong is twofold: (1) to provide entertainment and exercise for each individual user and (2) to promote social engagement within the group. We deployed DanceAlong in a cultural celebration at a senior community center and conducted evaluations. In this paper, we present the design process of DanceAlong, evaluations of DanceAlong, and design guidelines for creating similar interactive systems for the elderly.

Using visualizations to increase compliance in experience sampling

Experience sampling method (or ESM) is a common data collection method to understand user behavior and to evaluate ubiquitous computing technologies. However, ESM studies often demand too much time and commitment from participants, which leads to attrition and low compliance among participants. We introduce a new approach called experience sampling with feedback or ES+feedback that improves compliance by giving feedback to participants through various visualizations. Providing feedback to users makes the information personally relevant and increases the value of the study to participants, which increases their compliance. Our exploratory study shows that ES+feedback increases the compliance rate by 23%.