Evangelos Karapanos

CrisisTracker: crowdsourced social media curation for disaster awareness

Victims, volunteers, and relief organizations are increasingly using social media to report and act on large-scale events, as witnessed in the extensive coverage of the 2010-2012 Arab Spring uprisings and 2011 Japanese tsunami and nuclear disasters. Twitter® feeds consist of short messages, often in a nonstandard local language, requiring novel techniques to extract relevant situation awareness data. Existing approaches to mining social media are aimed at searching for specific information, or identifying aggregate trends, rather than providing narratives. We present CrisisTracker, an online system that in real time efficiently captures distributed situation awareness reports based on social media activity during large-scale events, such as natural disasters. CrisisTracker automatically tracks sets of keywords on Twitter and constructs stories by clustering related tweets on the basis of their lexical similarity. It integrates crowdsourcing techniques, enabling users to verify and analyze stories. We report our experiences from an 8-day CrisisTracker pilot deployment during 2012 focused on the Syrian civil war, which processed, on average, 446,000 tweets daily and reduced them to consumable stories through analytics and crowdsourcing. We discuss the effectiveness of CrisisTracker based on the usage and feedback from 48 domain experts and volunteer curators.

Citizen Motivation on the Go: The Role of Psychological Empowerment

Although advances in technology now enable people to communicate ‘anytime, anyplace’, it is not clear how citizens can be motivated to actually do so. This paper evaluates the impact of three principles of psychological empowerment, namely perceived self-efficacy, sense of community and causal importance, on public transport passengers’ motivation to report issues and complaints while on the move. A week-long study with 65 participants revealed that self-efficacy and causal importance increased participation in short bursts and increased perceptions of service quality over longer periods. Finally, we discuss the implications of these findings for citizen participation projects and reflect on design opportunities for mobile technologies that motivate citizen participation. RESEARCH HIGHLIGHTS • We evaluate three different factors of psychological empowerment in engaging users. • Perceived self-efficacy (PSE), causal importance (CI) and sense of community (SoC) were used. • PSE and CI lead to increased participation in short amounts of time. • PSE, CI and SoC lead to increased perceived public transportation service quality.

On the retrospective assessment of users' experiences over time: memory or actuality?

An alternative paradigm to longitudinal studies of user experience is proposed. We illustrate this paradigm through a number of recent tool-based methods. We conclude by raising a number of challenges that we need to address in order to establish this paradigm as a fruitful alternative to longitudinal studies.

The playful experiences (PLEX) framework as a guide for expert evaluation

The Playful Experiences (PLEX) framework is a categorization of playful experiences based on previous theoretical work on pleasurable experiences, game experiences, emotions, elements of play, and reasons why people play. While the framework has been successfully employed in design-related activities, its potential as an evaluation tool has not yet been studied. In this paper, we apply the PLEX framework in the evaluation of two game prototypes that explored novel physical interactions between mobile devices using Near-Field Communication, by means of three separate studies. Our results suggest that the PLEX framework provides anchor points for evaluators to reflect during heuristic evaluations. More broadly, the framework categories can be used as a checklist to assess different attributes of playfulness of a product or service.

Reconstructing experiences with iScale

We present iScale, a survey tool for the retrospective elicitation of longitudinal user experience data. iScale aims to minimize retrospection bias and employs graphing to impose a process during the reconstruction of ones experiences. Two versions, the constructive and the value-account iScale, were motivated by two distinct theories on how people reconstruct emotional experiences from memory. These two versions were tested in two separate studies. Study 1 aimed at providing qualitative insight into the use of iScale and compared its performance to that of free-hand graphing. Study 2 compared the two versions of iScale to free recall, a control condition that does not impose structure on the reconstruction process. Overall, iScale resulted in an increase in the amount, the richness, and the test-retest consistency of recalled information as compared to free recall. These results provide support for the viability of retrospective techniques as a cost-effective alternative to longitudinal studies.

Sustaining user engagement with behavior-change tools

Figure 1. Wearable activity trackers can provide many benefits, from empowerment and fostering a sense of responsibility with ones own health to opportunistic engagement in desired behaviors.

PLBSD: a platform for proactive location-based service discovery

We introduce a platform for the rapid prototyping of proactive location-based service discovery, proactive location-based services are conceptualised along three broad categories: location-triggered services chain-triggered services, proximity-triggered services, and illustrated through a number of usage scenarios. We report on a workshop with designers and researchers in the area of location-based services that resulted in a set of initial requirements for the platform. We describe how the platform aims at addressing these requirements, and illustrate the implemented features through the development of a proactive location-based application.

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 ones proclivity to experience playfulness differently. Finally, we reveal a four-factor structure of playfulness and discuss the implications for further theory development.

Network, personality and social capital

We present a study on the relationship between social network structure on Facebook and social capital, and how this relationship is moderated by personality traits. The findings suggest that ones number of friends does not necessarily have an effect on the amount of bridging social capital. Conversely, the extent of structural holes and isolated friends in the network have an effect on bridging social capital. In addition, individuals low on agreeableness benefit more from isolated friends in terms of bridging social capital. In terms of bonding social capital, introverts benefit more from networks with higher transitivity. Women overall report higher bonding social capital, but there are no significant gender differences when it comes to leveraging ones network structure for bridging or bonding social capital.

Modeling What Friendship Patterns on Facebook Reveal About Personality and Social Capital

In this study, we demonstrate how analysis of users’ social network structure—a topic that has remained until recently inconspicuous within Human-Computer Interaction (HCI) research on social systems—can contribute to our understanding of Social Networking Services (SNS) effect on users. Despite a consensus that SNS enhance peoples social capital, prior studies on SNS have provided inconsistent evidence on this process. In a multipronged study, we analyze personality, social capital, and Facebook data from a cohort of participants to model the extent to which ones SNS reflects aspects of his or personality and affects his bridging social capital. Our empirically validated model shows that empathy and conscientiousness influence the structural holes in ones social network, which in turn affects bridging social capital. These findings highlight the importance of network structure as an intermediary between ones personality and the social benefits one reaps from using SNS. Our work demonstrates how the implicit structural information embedded in users’ social networks can provide key insights into users’ personality and social capital.