News and Recent Projects


Honorable Mention for Best Paper @ Ubicomp’15

Together with Ruben Gouveia and Marc Hassenzahl, we received an Honorable Mention Award for Best Paper for the paper How Do We Engage With Activity Trackers? A Longitudinal Study of Habito. The Honorable Mention Award is given to a paper that was identified by the Program Committee as being among the top 5% of all submissions to UbiComp 2015. UbiComp is the premier interdisciplinary conference in the field of ubiquitous and pervasive computing, and a top-ranked international conference in computer... read more

How Do We Engage With Activity Trackers? A Longitudinal Study of Habito

We report on a 10-month in-the-wild study of the adoption, engagement and discontinuation of an activity tracker called Habito, by a sample of 256 users who installed the tracker on their own volition. We found ‘readiness’ to behavior change to be a strong predictor of adoption (which ranged from 56% to 20%). Among adopters, only a third updated their daily goal, which in turn impacted their physical activity levels. The use of the tracker was dominated by glances – brief, 5-sec sessions where users called the app to check their current activity levels with no further interaction, while users displayed true lack of interest in historical data. Textual feedback proved highly effective in fueling further engagement with the tracker as well as inducing physical activity. We propose three directions for design: designing for different levels of ‘readiness’, designing for multilayered and playful goal setting, and designing for sustained engagement.   Gouveia, R., Karapanos, E., Hassenzahl, M. (2015) How Do We Engage With Activity Trackers? A Longitudinal Study of Habito. In Proceedings of Ubicomp’15.  ... read more

Strong presence at Ubicomp’15

We are having a strong presence at Ubicomp’15, the premier conference in the area of Ubiquitous Computing, to be organized on Sept 7-11, 2015 in Osaka, Japan. We will be presenting the following papers:   Gouveia, R., Karapanos, E., Hassenzahl, M. (2015) How Do We Engage with Activity Trackers? A Longitudinal Study of Habito. In Proceedings of Ubicomp’15. Gouveia, R., Pereira, F., Caraban, A., Munson, S., Karapanos, E. (2015) You have 5 seconds: Designing Glanceable Feedback for Physical Activity Trackers. In adjunct proceedings of Ubicomp’15.  Ornelas, T., Caraban, A., Gouveia, R., Karapanos, E. (2015) CrowdWalk: Leveraging the Wisdom of the Crowd to Inspire Walking Activities. In adjunct proceedings of Ubicomp’15.  Caraban, A., Ferreira, M. J., Gouveia, R., Karapanos, E.(2015) Social Toothbrush: Fostering Family Nudging around Tooth Brushing Habits. In adjunct proceedings of Ubicomp’15. Ferreira, M.J., Caraban, A., Lyra, O., Belim, V., Karapanos, E. (2015) Why Alone? Sensing Children’s Social Interactions in the Playground. In adjunct proceedings of Ubicomp’15. ... read more

Crowdwalk: Leveraging the Wisdom of the Crowd to Inspire Walking Activities

We present CrowdWalk, a mobile app that leverages the wisdom of the crowd to produce location-based “walking challenges”, and thus attempts to assist behavior change through highlighting opportunities for physical activity. CrowdWalk infers users’ location and presents a list of walking activities that can be initiated from one’s current location. For instance, as users enter a building CrowdWalk may suggest taking the stairs. When entering a supermarket, users may be challenged to leave their shopping cart behind while walking back and forth to gather shopping items.   Ornelas, T., Caraban, A., Gouveia, R., Karapanos, E. (2015) CrowdWalk: Leveraging the Wisdom of the Crowd to Inspire Walking Activities. In Extended proceedings of Ubicomp’15.    Activities are contributed by users and are ordered by proximity and popularity. They are displayed within an “activity indicator circle”, depicting general information on an activity (such as name and description) as well as its contribution towards goal completion (e.g. walking around the campus will contribute an additional 2km towards your 15km daily goal, see Fig 1). Additional tips and comments are displayed, either provided by users (e.g. sharing experiences on a certain walking activity) or by the system (e.g. tips on the how to complete a certain walking activity). Users are further presented with a map (see Fig 2) view pinpointing the concrete location of an activity that reassures them of the accuracy of their location inference and allows browsing nearby activities.   Future work Individuals often struggle to move from the intention of attaining healthy lifestyles to the set goal. Long-lasting behaviors are hard to achieve, and despite the initial premises, effects of self-monitoring have been found to wear off with time [2]. With the design of CrowdWalk, we... read more

The "how, where and when" of physical activity

Despite their initial premise of physical-activity trackers in altering individuals’ lifestyles, recent studies have questioned their long-term efficacy. We present a study that sought to understand the walking activities individuals incorporate into their daily routines when attempting to be more physically activity – and specifically, the “why, how, when and where” of physical activity.   Ornelas, T., Caraban, A., Gouveia, R., Karapanos, E. (2015) CrowdWalk: Leveraging the Wisdom of the Crowd to Inspire Walking Activities. In Extended proceedings of Ubicomp’15.  A total of 65 participants (mean age=37, 46% male) successfully completed an online survey. All participants owned an activity tracker such as Fitbit, Jawbone Up or Nike Fuelband. They were mostly from the USA (46%), India (25%) and Australia (11%). They were recruited through Mechanical Turk and were rewarded with 0.30 euros for their participation. Responses were screened for quality by the first two authors.   Participants were asked to identify one “walking activity” embedded in their daily routines after adopting the tracker. We asked them to narrate it in detail as to when and where it takes place, their motives for performing it and the challenges they face (if any) in keeping up with it, as well as a number of closed questions relating to the estimated distance of walking activities and their frequency.   Findings Data was analyzed using affinity diagrams. All in all, twenty-seven distinct activities were identified. The vast majority (91%) was performed at least once per week, while 57% were performed on a daily basis.   DAILY WALKING ACTIVITIES CONTRIBUTE ON AVERAGE 2 KM Walking activities were mostly short in distance, with more than half (59%, N=38)... read more

You have 5 seconds: Designing Glanceable Feedback for Physical Activity Trackers

In our own work, we found that many activity tracker users lack the interest, skills, or motivation to reflect extensively on data about past behaviors. In fact, more than 70% of the usage of our activity tracker related to glances – brief, 5-second sessions where users check their current activity levels with no further interaction[5]. If glances are the dominant form of interaction with activity trackers, how can we design Glanceable Behavioral Feedback Interfaces (BFIs) to best support positive behaviors? In this paper we identify three directions for the design of Glanceable BFIs, namely: increasing the frequency of glances, increasing the impact of glances on physical activity, and transitioning glances to moments of exploration and learning.   Increasing the frequency of glances While glances were previously found to drive 70% of all interactions with a tracker [5], their frequency decreased over time. How can designs sustain such brief engagements with these tools? What design strategies entice users to return to review their data or view new content? We propose two design strategies towards increasing the frequency of glances: novel and scarce information.   Sustaining the novelty of information Motivated by the success of computer gaming and the airline industry, which regularly update content to sustain interest in games or safety instructions, we ask: what if feedback provided by an activity tracker is constantly updating? Prior work has shown dynamic content in smartphones, such as email and social media to lead to regular “checking habits” [9]. An example design operating upon this principle is Habito [5], a mobile app that sustains the novelty of feedback through constantly updating messages. In... read more

Footprint Tracker: Supporting Diary Studies with Lifelogging

As HCI shifts “to the wild”, in-situ methods such as Diary Methods and the Experience Sampling Method are gaining momentum. However, researchers have acknowledged the intrusiveness and lack of realism in these methods and have proposed solutions, notably through lightweight and rich media capture. In this paper we explore the concept of lifelogging as an alternative solution to these two challenges. We describe Footprint Tracker, a tool that allows the review of lifelogs with the aim to support recall and reflection over daily activities and experiences. In a field trial, we study how four different types of cues, namely visual, location, temporal and social context, trigger memories of recent events and associated emotions. We conclude with a number of implications for the design of lifelogging systems that support recall and reflection upon recent events as well as ones lying further in our past. Gouveia, R., and Karapanos, E. (2013) Footprint tracker: supporting diary studies with lifelogging. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems(CHI ’13). ACM, New York, NY, USA, 2921-2930.... read more

Sustaining User Engagement with Behavior Change Tools

Technologies for behavior change have immense potential. Consider, for instance, the case of physical activity trackers. Our healthcare systems are facing unprecedented challenges. Western lifestyles, now spreading throughout the world, have had a direct impact on the increase of chronic diseases, which today account for nearly 40 percent of mortality cases and 75 percent of healthcare costs, and are predicted to increase in frequency by 42 percent by 2023. Obesity alone has been estimated to account for 12 percent of the health-spending growth in the U.S. It is thus no surprise that policy makers and political figures are increasingly calling for a healthcare model that stresses patient-driven prevention rather than cures, such as Hillary Clinton’s call for a health initiative that focuses on “wellness, not sickness” and Gordon Brown’s call for an “NHS [National Health Service] of the future [being] one of patient power, with patients engaged and taking control over their own health and healthcare.”   Karapanos, E. (2015) Sustaining User Engagement with Behavior Change Tools, Interactions 22, 4 (June 2015), 48-52. Loading...   In this new landscape of healthcare, physical activity trackers have become a focus in both research and practice, as they can provide many benefits ranging from empowerment and people taking responsibility for their own health to opportunistic engagement in desired behaviors [1]. The market for wearable activity trackers such as Fitbit, Jawbone up, and Nike+ Fuelband has seen a rapid growth, estimated to have grossed $1.15 billion in 2014.   Sustaining User Engagement Is Challenging Despite significant recent advances, one could argue that research and practice in behavior-change technologies are still in their infancy. The... read more

Why Alone? Sensing Children’s Social Interactions in the Playground

With their increasingly sophisticated sensing capacity, mobile phones have been repeatedly used as pervasive, low-cost sensing devices in everyday life [5, 6]. In our line of work we attempt to employ mobile phones as a platform for sensing primary school students’ social participation in the school community.Over the past decade, schools have increasingly shifted towards inclusive education [10]. Rather than dividing students across regular and special education schools, inclusive education argues for ‘one school for all’. Next to its educational benefits, one of the main arguments for inclusive education is the increased social participation of children with learning and communication disabilities in regular, as opposed to special education schools [3]. However, despite the attention given to inclusive education in recent years, researchers have criticized a lack of empirical evidence on how exclusion is manifested in actual students’ behaviours [14]. Even when studies have tried to capture how exclusion is manifested in students’ social interactions within the class and during play time, their focus was limited to a number of school cases as well as particular dimensions of diversity, thus leading to an uncertainty of how such results may generalize to the larger population and how educational exclusion is manifested at large [7, 9, 15]. Existing methodological tools rely largely on selfreporting, either from teachers or students, and are thus susceptible to a number of biases. For instance, teachers have been found to overestimate the social participation of disadvantaged children [8]. In our line of work we attempt to develop technology that senses children’s social interactions in the playground [see [2, 11, 12] for earlier studies]. More specifically, we have... read more

PLEXQ: Towards a Playful Experiences Questionnaire

Playfulness is an important, but often neglected, design quality for interactive products. This paper presents a first step towards a validated questionnaire called PLEXQ, which measures 17 different facets of playful user experiences. We describe the development and validation of the questionnaire, from the generation of 231 items, to the current questionnaire consisting of 17 constructs of playfulness, each measured through three items. Using PLEXQ we discuss the nature of playfulness by looking at the role of age, gender, and product type in one’s proclivity to experience playfulness differently. Finally, we reveal a four-factor structure of playfulness and discuss the implications for further theory development.   Boberg, M., Karapanos, E., Holopainen, J., Lucero, A. (2015) PLEXQ: Towards a Playful Experiences Questionnaire, In Proceedings of CHI Play’15.   ... read more

CMU Portugal Grant awarded

Together with Jodi Forlizzi (Carnegie Mellon University) we received a research grant to study the long-term impact of personal health informatics tools. Funded by FCT (Portuguese Foundation for Science and Technology) under the Carnegie Mellon | Portugal Early Bird 2013 program (CMU|Pt EPB), this project will seek to understand and design for prolonged engagement with wearable activity trackers.   Triggered by recent advances in sensor technology and ultra low power microcontrollers, the market of wearable activity trackers, such as Fitbit, Jawbone up, andNike+ Fuelband, has grossed over $230M in 2013 and is expected to continue its growth. With chronic diseases such as diabetes, cardiovascular and respiratory diseases accounting for nearly 40% of mortality cases and 75% of health care costs, and obesity alone accounting for an estimated 12 percent of the health spending growth in the U.S., wearable activity trackers promise a new health care model that stresses patient-driven prevention.   Yet, researchers have raised concerns over the plausible wear-off of any initial effects on users’ behaviors. A recent survey has found that over a third of owners of wearable activity trackers have discarded them within six months of use. It remains unclear whether this is because healthy routines became established or whether the trackers lost their appeal over time.   The goal of the project is to understand the factors that drive users’ long-term engagement with wearable activity trackers, and to design new solutions for prolonged... read more

User Experience Over Time: An Initial Framework

A recent trend in Human-Computer Interaction (HCI) research addresses human needs that go beyond the instrumental, resulting in an increasing body of knowledge about how users form overall evaluative judgments on the quality of interactive products. An aspect largely neglected so far is that of temporality, i.e. how the quality of users’ experience develops over time. This paper presents an in-depth, five-week ethnographic study that followed 6 individuals during an actual purchase of the Apple iPhone. We found prolonged use to be motivated by different qualities than the ones that provided positive initial experiences. Overall, while early experiences seemed to relate mostly to hedonic aspects of product use, prolonged experiences became increasingly more tied to aspects reflecting how the product becomes meaningful in one’s life. Based on the findings, we promote three directions for CHI practice: designing for meaningful mediation, designing for daily rituals, and designing for the self.   Karapanos, E., Zimmerman, J., Forlizzi, J., & Martens, J. B. (2009). User experience over time: an initial framework. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (pp. 729-738). ACM.   Loading...... read more

User Experience Over Time

The way we experience and evaluate interactive products develops over time. An exploratory study aimed at understanding how users form evaluative judgments during the first experiences with a product as well as after four weeks of use. Goodness, an evaluative judgment related to the overall satisfaction with the product, was largely formed on the basis of pragmatic aspects (i.e. utility and usability) during the first experi- ences; after four weeks of use identification (i.e. what the products expresses about its owner) became a dominant aspect of how good a product is. Surprisingly, beauty judgments were largely affected by stimulation (e.g. novelty) during the first experiences. Over time stimulation lost its power to make the product beautiful in the users’ eyes.   Karapanos, E., Hassenzahl, M., and Martens, J.B. (2008) User experience over time. In CHI ’08 Extended Abstracts on Human Factors in Computing Systems (CHI EA ’08). ACM, New York, NY, USA, 3561-3566.     Loading...... read more