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Matthew Kay

University of Michigan, School of Information, Faculty Member

University of Washington, Computer Science & Engineering, Graduate Student

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My research spans several areas, from understanding people, to building interactive systems, to designing visualizations, to modeling: human−computer interaction, information visualization, and computer science. My current research is specifically on usable statistics and communicating uncertainty.
Supervisors: Julie Kientz and Shwetak Patel

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University of Hamburg

University of Adelaide

Loc Nguyen's Academic Network

Independent Scholar

Nankai University

University of Hamburg

Antonia Krefeld-Schwalb

Patrizio Tressoldi

Università degli Studi di Padova

University of Groningen

Arizona State University

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Papers by Matthew Kay

Researcher-Centered Design of Statistics: Why Bayesian Statistics Better Fit the Culture and Incentives of HCI

CHI '16: Proceedings of the 34th Annual ACM Conference on Human Factors in Computing Systems

A core tradition of HCI lies in the experimental evaluation of the effects of techniques and inte... more A core tradition of HCI lies in the experimental evaluation of the effects of techniques and interfaces to determine if they are useful for achieving their purpose. However, our individual analyses tend to stand alone, and study results rarely accrue in more precise estimates via meta-analysis: in a literature search, we found only 56 meta-analyses in HCI in the ACM Digital Library, 3 of which were published at CHI (often called the top HCI venue). Yet meta-analysis is the gold standard for demonstrating robust quantitative knowledge. We treat this as a user-centered design problem: the failure to accrue quantitative knowledge is not the users' (i.e. researchers') failure, but a failure to consider those users' needs when designing statistical practice. Using simulation, we compare hypothetical publication worlds following existing frequentist against Bayesian practice. We show that Bayesian analysis yields more precise effects with each new study, facilitating knowledge accrual without traditional meta-analyses. Bayesian practices also allow more principled conclusions from small-n studies of novel techniques. These advantages make Bayesian practices a likely better fit for the culture and incentives of the field. Instead of admonishing ourselves to spend resources on larger studies, we propose using tools that more appropriately analyze small studies and encourage knowledge ac-crual from one study to the next. We also believe Bayesian methods can be adopted from the bottom up without the need for new incentives for replication or meta-analysis. These techniques offer the potential for a more user-(i.e. researcher-) centered approach to statistical analysis in HCI.

When (ish) is My Bus? User-centered Visualizations of Uncertainty in Everyday, Mobile Predictive Systems

CHI '16: Proceedings of the 34th Annual ACM Conference on Human Factors in Computing Systems

Users often rely on realtime predictions in everyday contexts like riding the bus, but may not gr... more Users often rely on realtime predictions in everyday contexts like riding the bus, but may not grasp that such predictions are subject to uncertainty. Existing uncertainty visual-izations may not align with user needs or how they naturally reason about probability. We present a novel mobile interface design and visualization of uncertainty for transit predictions on mobile phones based on discrete outcomes. To develop it, we identified domain specific design requirements for visualizing uncertainty in transit prediction through: 1) a literature review, 2) a large survey of users of a popular realtime transit application, and 3) an iterative design process. We present several candidate visualizations of uncertainty for realtime transit predictions in a mobile context, and we propose a novel discrete representation of continuous outcomes designed for small screens, quantile dotplots. In a controlled experiment we find that quantile dotplots reduce the variance of probabilistic estimates by ~1.15 times compared to density plots and facilitate more confident estimation by end-users in the context of realtime transit prediction scenarios.

Beyond Weber’s Law: A Second Look at Ranking Visualizations of Correlation

Models of human perception – including perceptual “laws” – can be valuable tools for deriving vis... more Models of human perception – including perceptual “laws” – can be valuable tools for deriving visualization design recommendations. However, it is important to assess the explanatory power of such models when using them to inform design. We present a secondary analysis of data previously used to rank the effectiveness of bivariate visualizations for assessing correlation (measured with Pearson’s r) according to the well-known Weber-Fechner Law. Beginning with the model of Harrison et al. [1], we present a sequence of refinements including incorporation of individual differences, log transformation, censored regression, and adoption of Bayesian statistics. Our model incorporates all observations dropped from the original analysis, including data near ceilings caused by the data collection process and entire visualizations dropped due to large numbers of observations worse than chance. This model deviates from Weber’s Law, but provides improved predictive accuracy and generalization. Using Bayesian credibility intervals, we derive a partial ranking that groups visualizations with similar performance, and we give precise estimates of the difference in performance between these groups. We find that compared to other visualizations, scatterplots are unique in combining low variance between individuals and high precision on both positively- and negatively- correlated data. We conclude with a discussion of the value of data sharing and replication, and share implications for modeling similar experimental data.

Unequal Representation and Gender Stereotypes in Image Search Results for Occupations

Proceedings of the 33rd Annual ACM Conference on Human Factors in Computing Systems - CHI '15, 2015

Information environments have the power to affect people's perceptions and behaviors. In this pap... more Information environments have the power to affect people's perceptions and behaviors. In this paper, we present the results of studies in which we characterize the gender bias present in image search results for a variety of occupations. We experimentally evaluate the effects of bias in image search results on the images people choose to represent those careers and on people's perceptions of the prevalence of men and women in each occupation. We find evidence for both stereotype exaggeration and systematic underrepresentation of women in search results. We also find that people rate search results higher when they are consistent with stereotypes for a career, and shifting the representation of gender in image search results can shift people's perceptions about real-world distributions. We also discuss tensions between desires for high-quality results and broader societal goals for equality of representation in this space.

There's no such thing as gaining a pound: Reconsidering the Bathroom Scale User Interface

Proceedings of the 2013 ACM international joint conference on Pervasive and ubiquitous computing - UbiComp '13, 2013

The weight scale is perhaps the most ubiquitous health sensor of all and is important to many hea... more The weight scale is perhaps the most ubiquitous health sensor of all and is important to many health and lifestyle decisions, but its fundamental interface-a single numerical estimate of a person's current weight-has remained largely unchanged for 100 years. An opportunity exists to impact public health by re-considering this pervasive interface. Toward that end, we investigated the correspondence between consumers' perceptions of weight data and the realities of weight fluctuation. Through an analysis of online product reviews, a journaling study on weight fluctuations, expert interviews, and a large-scale survey of scale users, we found that consumers' perception of weight scale behavior is often disconnected from scales' capabilities and from clinical relevance, and that accurate understanding of weight fluctuation is associated with greater trust in the scale itself. We propose significant changes to how weight data should be presented and discuss broader implications for the design of other ubiquitous health sensing devices.

How Good is 85%? A Survey Tool to Connect Classifier Evaluation to Acceptability of Accuracy

Proceedings of the 33rd Annual ACM Conference on Human Factors in Computing Systems - CHI '15, 2015

Many HCI and ubiquitous computing systems are characterized by two important properties: their ou... more Many HCI and ubiquitous computing systems are characterized by two important properties: their output is uncertain-it has an associated accuracy that researchers attempt to optimize-and this uncertainty is user-facing-it directly affects the quality of the user experience. Novel classifiers are typically evaluated using measures like the F 1 scorebut given an F-score of (e.g.) 0.85, how do we know whether this performance is good enough? Is this level of uncertainty actually tolerable to users of the intended application-and do people weight precision and recall equally? We set out to develop a survey instrument that can systematically answer such questions. We introduce a new measure, acceptability of accuracy, and show how to predict it based on measures of classifier accuracy. Out tool allows us to systematically select an objective function to optimize during classifier evaluation, but can also offer new insights into how to design feedback for user-facing classification systems (e.g., by combining a seemingly-low-performing classifier with appropriate feedback to make a highly usable system). It also reveals potential issues with the ubiquitous F1-measure as applied to user-facing systems.

Lullaby: A capture & access system for understanding the sleep environment

Proceedings of the 2012 ACM Conference on Ubiquitous Computing (UbiComp '12), 2012

The bedroom environment can have a significant impact on the quality of a person's sleep. Experts... more The bedroom environment can have a significant impact on the quality of a person's sleep. Experts recommend sleeping in a room that is cool, dark, quiet, and free from disruptors to ensure the best quality sleep. However, it is sometimes difficult for a person to assess which factors in the environment may be causing disrupted sleep. In this paper, we present the design, implementation, and initial evaluation of a capture and access system, called Lullaby. Lullaby combines temperature, light, and motion sensors, audio and photos, and an off-the-shelf sleep sensor to provide a comprehensive recording of a person's sleep. Lullaby allows users to review graphs and access recordings of factors relating to their sleep quality and environmental conditions to look for trends and potential causes of sleep disruptions. In this paper, we report results of a feasibility study where participants (N=4) used Lullaby in their homes for two weeks. Based on our experiences, we discuss design insights for sleep technologies, capture and access applications, and personal informatics tools.

PVT-Touch: Adapting a Reaction Time Test for Touchscreen Devices

by Julie Kientz, Matthew Kay, and Jacob Wobbrock

Proceedings of the ICTs for improving Patients Rehabilitation Research Techniques, 2013

The Psychomotor Vigilance Task (PVT) is a validated reaction time (RT) test used to assess aspect... more The Psychomotor Vigilance Task (PVT) is a validated reaction time (RT) test used to assess aspects of sleep loss including alertness and sleepiness. PVT typically requires a physical button to assess RT, which minimizes the effect of execution time (the time taken to perform a gesture) on RT. When translating this application to mobile devices, a touchscreen version is useful for widespread in situ sleepiness assessments to produce more ecologically valid data. We describe the Android-based implementation of a touchscreen version of PVT, called PVT-Touch. In an evaluation (N=20), we compared four different touchscreen input techniques to a physical button: touch down, finger lift, finger tilt, and goal crossing. We found that touch down was comparable to the physical button approach used in traditional PVT in execution time and in several measures associated with sleepiness, and was preferred by most participants. We also found that finger lift may be a more precise but less intuitive measure, which may warrant further study.

SleepTight: Low-burden, Self-monitoring Technology for Capturing and Reflecting on Sleep Behaviors

Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing - UbiComp '15, 2015

Manual tracking of health behaviors affords many benefits, including increased awareness and enga... more Manual tracking of health behaviors affords many benefits, including increased awareness and engagement. However, the capture burden makes long-term manual tracking challenging. In this study on sleep tracking, we examine ways to reduce the capture burden of manual tracking while leveraging its benefits. We report on the design and evaluation of SleepTight, a low-burden, self-monitoring tool that leverages the Android's widgets both to reduce the capture burden and to improve access to information. Through a four-week deployment study (N = 22), we found that participants who used SleepTight with the widgets enabled had a higher sleep diary compliance rate (92%) than participants who used SleepTight without the widgets (73%). In addition, the widgets improved information access and encouraged self-reflection. We discuss how to leverage widgets to help people collect more data and improve access to information, and more broadly, how to design successful manual self-monitoring tools that support self-reflection.

Consumer Sleep Technologies: A Review of the Landscape

Journal of clinical sleep medicine: JCSM: official publication of the American Academy of Sleep Medicine

To review sleep related consumer technologies, including mobile electronic device &amp;amp;am... more To review sleep related consumer technologies, including mobile electronic device &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;apps,&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; wearable devices, and other technologies. Validation and methodological transparency, the effect on clinical sleep medicine, and various social, legal, and ethical issues are discussed. We reviewed publications from the digital libraries of the Association for Computing Machinery, Institute of Electrical and Electronics Engineers, and PubMed; publications from consumer technology websites; and mobile device app marketplaces. Search terms included &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;sleep technology,&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;sleep app,&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;sleep monitoring.&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; Consumer sleep technologies are categorized by delivery platform including mobile device apps (integrated with a mobile operating system and utilizing mobile device functions such as the camera or microphone), wearable devices (on the body or attached to clothing), embedded devices (integrated into furniture or other fixtures in the native sleep environment), accessory appliances, and conventional desktop/website resources. Their primary goals include facilitation of sleep induction or wakening, self-guided sleep assessment, entertainment, social connection, information sharing, and sleep education. Consumer sleep technologies are changing the landscape of sleep health and clinical sleep medicine. These technologies have the potential to both improve and impair collective and individual sleep health depending on method of implementation.

Challenges in personal health tracking: The data isn’t enough

XRDS: Crossroads, The ACM Magazine for Students, 2014

Increasingly, personal health data can be tracked and integrated from numerous streams quickly an... more

Textured agreements: Re-envisioning Electronic Consent

Proceedings of the Sixth Symposium on Usable Privacy and Security - SOUPS '10, 2010

The changing nature of (ubiquitous) computing

XRDS: Crossroads, The ACM Magazine for Students, 2012

Communicating software agreement content using narrative pictograms

Proceedings of the 28th of the international conference extended abstracts on Human factors in computing systems - CHI EA '10, 2010

Perceptions and practices of usability in the free/open source software (FoSS) community

Proceedings of the 28th international conference on Human factors in computing systems - CHI '10, 2010

This paper presents results from a study examining perceptions and practices of usability in the ... more This paper presents results from a study examining perceptions and practices of usability in the free/open source software (FOSS) community. 27 individuals associated with 11 different FOSS projects were interviewed to understand how they think about, act on, and are motivated to address usability issues. Our results indicate that FOSS project members possess rather sophisticated notions of software usability, which collectively mirror definitions commonly found in HCI textbooks. Our study also uncovered a wide range of practices that ultimately work to improve software usability. Importantly, these activities are typically based on close, direct interpersonal relationships between developers and their core users, a group of users who closely follow the project and provide high quality, respected feedback. These relationships, along with positive feedback from other users, generate social rewards that serve as the primary motivations for attending to usability issues on a dayto-day basis. These findings suggest a need to reconceptualize HCI methods to better fit this culture of practice and its corresponding value system.

Ingimp: introducing instrumentation to an end-user open source application

Proceeding of the twenty-sixth annual CHI conference on Human factors in computing systems - CHI '08, 2008

Open source projects are gradually incorporating usability methods into their development practic... more Open source projects are gradually incorporating usability methods into their development practices, but there are still many unmet needs. One particular need for nearly any open source project is data that describes its user base, including information indicating how the software is actually used in practice. This paper presents the concept of open instrumentation, or the augmentation of an open source application to openly collect and publicly disseminate rich application usage data. We demonstrate the concept of open instrumentation in ingimp, a version of the open source GNU Image Manipulation Program that has been modified to collect end-user usage data. ingimp automatically collects five types of data: The commands used, high-level user interface events, overall features of the user's documents, summaries of the user's general computing environment, and users' own descriptions of their planned tasks. In the spirit of open source software, all collected data are made available for anyone to download and analyze. This paper's primary contributions lie in presenting the overall design of ingimp, with a particular focus on how the design addresses two prominent issues in open instrumentation: privacy and motivating use.

Techniques and heuristics for improving the visual design of software agreements

Disasters in personal informatics: the unpublished stories of failure and lessons learned

Biological rhythms and technology

by Matthew Kay and Geri Gay

Proceedings of the extended abstracts of the 32nd annual ACM conference on Human factors in computing systems - CHI EA '14, 2014

Biological rhythms enable living organisms to adapt and live with periodical environmental change... more Biological rhythms enable living organisms to adapt and live with periodical environmental changes, such as variation in the relative position of the earth and the sun. Internal rhythms, like body temperature and sleep-wake cycle, are driven by numerous biological processes and can be maintained even in the absence of external environmental cues. These rhythms affect how we feel, think, and act. They are profoundly important for our health, quality of sleep, and mood. Yet the digital devices we use are ignorant of our biology. They respond uniformly to our touch and click. Recently there has been a considerable increase of research within the HCI community to support behavior change, personal insight, and increase productivity. This workshop will bring together researchers in sleep, wellbeing, and circadian rhythms to discuss the possibility of rhythm systems: technologies that play to the strengths of our biology. It will investigate how HCI can complement our biological rhythms and will focus on two areas: measurement and intervention.

Evaluating Zeo and Fitbit for Tracking Sleep Behaviors

Researcher-Centered Design of Statistics: Why Bayesian Statistics Better Fit the Culture and Incentives of HCI

CHI '16: Proceedings of the 34th Annual ACM Conference on Human Factors in Computing Systems

A core tradition of HCI lies in the experimental evaluation of the effects of techniques and inte... more A core tradition of HCI lies in the experimental evaluation of the effects of techniques and interfaces to determine if they are useful for achieving their purpose. However, our individual analyses tend to stand alone, and study results rarely accrue in more precise estimates via meta-analysis: in a literature search, we found only 56 meta-analyses in HCI in the ACM Digital Library, 3 of which were published at CHI (often called the top HCI venue). Yet meta-analysis is the gold standard for demonstrating robust quantitative knowledge. We treat this as a user-centered design problem: the failure to accrue quantitative knowledge is not the users' (i.e. researchers') failure, but a failure to consider those users' needs when designing statistical practice. Using simulation, we compare hypothetical publication worlds following existing frequentist against Bayesian practice. We show that Bayesian analysis yields more precise effects with each new study, facilitating knowledge accrual without traditional meta-analyses. Bayesian practices also allow more principled conclusions from small-n studies of novel techniques. These advantages make Bayesian practices a likely better fit for the culture and incentives of the field. Instead of admonishing ourselves to spend resources on larger studies, we propose using tools that more appropriately analyze small studies and encourage knowledge ac-crual from one study to the next. We also believe Bayesian methods can be adopted from the bottom up without the need for new incentives for replication or meta-analysis. These techniques offer the potential for a more user-(i.e. researcher-) centered approach to statistical analysis in HCI.

When (ish) is My Bus? User-centered Visualizations of Uncertainty in Everyday, Mobile Predictive Systems

CHI '16: Proceedings of the 34th Annual ACM Conference on Human Factors in Computing Systems

Users often rely on realtime predictions in everyday contexts like riding the bus, but may not gr... more Users often rely on realtime predictions in everyday contexts like riding the bus, but may not grasp that such predictions are subject to uncertainty. Existing uncertainty visual-izations may not align with user needs or how they naturally reason about probability. We present a novel mobile interface design and visualization of uncertainty for transit predictions on mobile phones based on discrete outcomes. To develop it, we identified domain specific design requirements for visualizing uncertainty in transit prediction through: 1) a literature review, 2) a large survey of users of a popular realtime transit application, and 3) an iterative design process. We present several candidate visualizations of uncertainty for realtime transit predictions in a mobile context, and we propose a novel discrete representation of continuous outcomes designed for small screens, quantile dotplots. In a controlled experiment we find that quantile dotplots reduce the variance of probabilistic estimates by ~1.15 times compared to density plots and facilitate more confident estimation by end-users in the context of realtime transit prediction scenarios.

Beyond Weber’s Law: A Second Look at Ranking Visualizations of Correlation

Models of human perception – including perceptual “laws” – can be valuable tools for deriving vis... more Models of human perception – including perceptual “laws” – can be valuable tools for deriving visualization design recommendations. However, it is important to assess the explanatory power of such models when using them to inform design. We present a secondary analysis of data previously used to rank the effectiveness of bivariate visualizations for assessing correlation (measured with Pearson’s r) according to the well-known Weber-Fechner Law. Beginning with the model of Harrison et al. [1], we present a sequence of refinements including incorporation of individual differences, log transformation, censored regression, and adoption of Bayesian statistics. Our model incorporates all observations dropped from the original analysis, including data near ceilings caused by the data collection process and entire visualizations dropped due to large numbers of observations worse than chance. This model deviates from Weber’s Law, but provides improved predictive accuracy and generalization. Using Bayesian credibility intervals, we derive a partial ranking that groups visualizations with similar performance, and we give precise estimates of the difference in performance between these groups. We find that compared to other visualizations, scatterplots are unique in combining low variance between individuals and high precision on both positively- and negatively- correlated data. We conclude with a discussion of the value of data sharing and replication, and share implications for modeling similar experimental data.

Unequal Representation and Gender Stereotypes in Image Search Results for Occupations

Proceedings of the 33rd Annual ACM Conference on Human Factors in Computing Systems - CHI '15, 2015

Information environments have the power to affect people's perceptions and behaviors. In this pap... more Information environments have the power to affect people's perceptions and behaviors. In this paper, we present the results of studies in which we characterize the gender bias present in image search results for a variety of occupations. We experimentally evaluate the effects of bias in image search results on the images people choose to represent those careers and on people's perceptions of the prevalence of men and women in each occupation. We find evidence for both stereotype exaggeration and systematic underrepresentation of women in search results. We also find that people rate search results higher when they are consistent with stereotypes for a career, and shifting the representation of gender in image search results can shift people's perceptions about real-world distributions. We also discuss tensions between desires for high-quality results and broader societal goals for equality of representation in this space.

There's no such thing as gaining a pound: Reconsidering the Bathroom Scale User Interface

Proceedings of the 2013 ACM international joint conference on Pervasive and ubiquitous computing - UbiComp '13, 2013

The weight scale is perhaps the most ubiquitous health sensor of all and is important to many hea... more The weight scale is perhaps the most ubiquitous health sensor of all and is important to many health and lifestyle decisions, but its fundamental interface-a single numerical estimate of a person's current weight-has remained largely unchanged for 100 years. An opportunity exists to impact public health by re-considering this pervasive interface. Toward that end, we investigated the correspondence between consumers' perceptions of weight data and the realities of weight fluctuation. Through an analysis of online product reviews, a journaling study on weight fluctuations, expert interviews, and a large-scale survey of scale users, we found that consumers' perception of weight scale behavior is often disconnected from scales' capabilities and from clinical relevance, and that accurate understanding of weight fluctuation is associated with greater trust in the scale itself. We propose significant changes to how weight data should be presented and discuss broader implications for the design of other ubiquitous health sensing devices.

How Good is 85%? A Survey Tool to Connect Classifier Evaluation to Acceptability of Accuracy

Proceedings of the 33rd Annual ACM Conference on Human Factors in Computing Systems - CHI '15, 2015

Many HCI and ubiquitous computing systems are characterized by two important properties: their ou... more Many HCI and ubiquitous computing systems are characterized by two important properties: their output is uncertain-it has an associated accuracy that researchers attempt to optimize-and this uncertainty is user-facing-it directly affects the quality of the user experience. Novel classifiers are typically evaluated using measures like the F 1 scorebut given an F-score of (e.g.) 0.85, how do we know whether this performance is good enough? Is this level of uncertainty actually tolerable to users of the intended application-and do people weight precision and recall equally? We set out to develop a survey instrument that can systematically answer such questions. We introduce a new measure, acceptability of accuracy, and show how to predict it based on measures of classifier accuracy. Out tool allows us to systematically select an objective function to optimize during classifier evaluation, but can also offer new insights into how to design feedback for user-facing classification systems (e.g., by combining a seemingly-low-performing classifier with appropriate feedback to make a highly usable system). It also reveals potential issues with the ubiquitous F1-measure as applied to user-facing systems.

Lullaby: A capture & access system for understanding the sleep environment

Proceedings of the 2012 ACM Conference on Ubiquitous Computing (UbiComp '12), 2012

The bedroom environment can have a significant impact on the quality of a person's sleep. Experts... more The bedroom environment can have a significant impact on the quality of a person's sleep. Experts recommend sleeping in a room that is cool, dark, quiet, and free from disruptors to ensure the best quality sleep. However, it is sometimes difficult for a person to assess which factors in the environment may be causing disrupted sleep. In this paper, we present the design, implementation, and initial evaluation of a capture and access system, called Lullaby. Lullaby combines temperature, light, and motion sensors, audio and photos, and an off-the-shelf sleep sensor to provide a comprehensive recording of a person's sleep. Lullaby allows users to review graphs and access recordings of factors relating to their sleep quality and environmental conditions to look for trends and potential causes of sleep disruptions. In this paper, we report results of a feasibility study where participants (N=4) used Lullaby in their homes for two weeks. Based on our experiences, we discuss design insights for sleep technologies, capture and access applications, and personal informatics tools.

PVT-Touch: Adapting a Reaction Time Test for Touchscreen Devices

by Julie Kientz, Matthew Kay, and Jacob Wobbrock

Proceedings of the ICTs for improving Patients Rehabilitation Research Techniques, 2013

The Psychomotor Vigilance Task (PVT) is a validated reaction time (RT) test used to assess aspect... more The Psychomotor Vigilance Task (PVT) is a validated reaction time (RT) test used to assess aspects of sleep loss including alertness and sleepiness. PVT typically requires a physical button to assess RT, which minimizes the effect of execution time (the time taken to perform a gesture) on RT. When translating this application to mobile devices, a touchscreen version is useful for widespread in situ sleepiness assessments to produce more ecologically valid data. We describe the Android-based implementation of a touchscreen version of PVT, called PVT-Touch. In an evaluation (N=20), we compared four different touchscreen input techniques to a physical button: touch down, finger lift, finger tilt, and goal crossing. We found that touch down was comparable to the physical button approach used in traditional PVT in execution time and in several measures associated with sleepiness, and was preferred by most participants. We also found that finger lift may be a more precise but less intuitive measure, which may warrant further study.

SleepTight: Low-burden, Self-monitoring Technology for Capturing and Reflecting on Sleep Behaviors

Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing - UbiComp '15, 2015

Manual tracking of health behaviors affords many benefits, including increased awareness and enga... more Manual tracking of health behaviors affords many benefits, including increased awareness and engagement. However, the capture burden makes long-term manual tracking challenging. In this study on sleep tracking, we examine ways to reduce the capture burden of manual tracking while leveraging its benefits. We report on the design and evaluation of SleepTight, a low-burden, self-monitoring tool that leverages the Android's widgets both to reduce the capture burden and to improve access to information. Through a four-week deployment study (N = 22), we found that participants who used SleepTight with the widgets enabled had a higher sleep diary compliance rate (92%) than participants who used SleepTight without the widgets (73%). In addition, the widgets improved information access and encouraged self-reflection. We discuss how to leverage widgets to help people collect more data and improve access to information, and more broadly, how to design successful manual self-monitoring tools that support self-reflection.

Consumer Sleep Technologies: A Review of the Landscape

Journal of clinical sleep medicine: JCSM: official publication of the American Academy of Sleep Medicine

To review sleep related consumer technologies, including mobile electronic device &amp;amp;am... more To review sleep related consumer technologies, including mobile electronic device &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;apps,&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; wearable devices, and other technologies. Validation and methodological transparency, the effect on clinical sleep medicine, and various social, legal, and ethical issues are discussed. We reviewed publications from the digital libraries of the Association for Computing Machinery, Institute of Electrical and Electronics Engineers, and PubMed; publications from consumer technology websites; and mobile device app marketplaces. Search terms included &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;sleep technology,&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;sleep app,&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;sleep monitoring.&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; Consumer sleep technologies are categorized by delivery platform including mobile device apps (integrated with a mobile operating system and utilizing mobile device functions such as the camera or microphone), wearable devices (on the body or attached to clothing), embedded devices (integrated into furniture or other fixtures in the native sleep environment), accessory appliances, and conventional desktop/website resources. Their primary goals include facilitation of sleep induction or wakening, self-guided sleep assessment, entertainment, social connection, information sharing, and sleep education. Consumer sleep technologies are changing the landscape of sleep health and clinical sleep medicine. These technologies have the potential to both improve and impair collective and individual sleep health depending on method of implementation.

Challenges in personal health tracking: The data isn’t enough

XRDS: Crossroads, The ACM Magazine for Students, 2014

Increasingly, personal health data can be tracked and integrated from numerous streams quickly an... more

Textured agreements: Re-envisioning Electronic Consent

Proceedings of the Sixth Symposium on Usable Privacy and Security - SOUPS '10, 2010

The changing nature of (ubiquitous) computing

XRDS: Crossroads, The ACM Magazine for Students, 2012

Communicating software agreement content using narrative pictograms

Proceedings of the 28th of the international conference extended abstracts on Human factors in computing systems - CHI EA '10, 2010

Perceptions and practices of usability in the free/open source software (FoSS) community

Proceedings of the 28th international conference on Human factors in computing systems - CHI '10, 2010

This paper presents results from a study examining perceptions and practices of usability in the ... more This paper presents results from a study examining perceptions and practices of usability in the free/open source software (FOSS) community. 27 individuals associated with 11 different FOSS projects were interviewed to understand how they think about, act on, and are motivated to address usability issues. Our results indicate that FOSS project members possess rather sophisticated notions of software usability, which collectively mirror definitions commonly found in HCI textbooks. Our study also uncovered a wide range of practices that ultimately work to improve software usability. Importantly, these activities are typically based on close, direct interpersonal relationships between developers and their core users, a group of users who closely follow the project and provide high quality, respected feedback. These relationships, along with positive feedback from other users, generate social rewards that serve as the primary motivations for attending to usability issues on a dayto-day basis. These findings suggest a need to reconceptualize HCI methods to better fit this culture of practice and its corresponding value system.

Ingimp: introducing instrumentation to an end-user open source application

Proceeding of the twenty-sixth annual CHI conference on Human factors in computing systems - CHI '08, 2008

Open source projects are gradually incorporating usability methods into their development practic... more Open source projects are gradually incorporating usability methods into their development practices, but there are still many unmet needs. One particular need for nearly any open source project is data that describes its user base, including information indicating how the software is actually used in practice. This paper presents the concept of open instrumentation, or the augmentation of an open source application to openly collect and publicly disseminate rich application usage data. We demonstrate the concept of open instrumentation in ingimp, a version of the open source GNU Image Manipulation Program that has been modified to collect end-user usage data. ingimp automatically collects five types of data: The commands used, high-level user interface events, overall features of the user's documents, summaries of the user's general computing environment, and users' own descriptions of their planned tasks. In the spirit of open source software, all collected data are made available for anyone to download and analyze. This paper's primary contributions lie in presenting the overall design of ingimp, with a particular focus on how the design addresses two prominent issues in open instrumentation: privacy and motivating use.

Techniques and heuristics for improving the visual design of software agreements

Disasters in personal informatics: the unpublished stories of failure and lessons learned

Biological rhythms and technology

by Matthew Kay and Geri Gay

Proceedings of the extended abstracts of the 32nd annual ACM conference on Human factors in computing systems - CHI EA '14, 2014

Biological rhythms enable living organisms to adapt and live with periodical environmental change... more Biological rhythms enable living organisms to adapt and live with periodical environmental changes, such as variation in the relative position of the earth and the sun. Internal rhythms, like body temperature and sleep-wake cycle, are driven by numerous biological processes and can be maintained even in the absence of external environmental cues. These rhythms affect how we feel, think, and act. They are profoundly important for our health, quality of sleep, and mood. Yet the digital devices we use are ignorant of our biology. They respond uniformly to our touch and click. Recently there has been a considerable increase of research within the HCI community to support behavior change, personal insight, and increase productivity. This workshop will bring together researchers in sleep, wellbeing, and circadian rhythms to discuss the possibility of rhythm systems: technologies that play to the strengths of our biology. It will investigate how HCI can complement our biological rhythms and will focus on two areas: measurement and intervention.

Evaluating Zeo and Fitbit for Tracking Sleep Behaviors