Mattias Rost

Representation and communication: challenges in interpreting large social media datasets

Online services provide a range of opportunities for understanding human behaviour through the large aggregate data sets that their operation collects. Yet the data sets they collect do not unproblematically model or mirror the world events. In this paper we use data from Foursquare, a popular location check-in service, to argue for the importance of analysing social media as a communicative rather than representational system. Drawing on logs of all Foursquare check-ins over eight weeks we highlight four features of Foursquares use: the relationship between attendance and check-ins, event check-ins, commercial incentives to check-in, and lastly humorous check-ins These points show how large data analysis is affected by the end user uses to which social networks are put.

Research in the large. using app stores, markets, and other wide distribution channels in Ubicomp research

The mobile phones that people use in their daily lives now run advanced applications and come equipped with sensors once only available in custom hardware in UbiComp research. At the same time application distribution has become increasingly simple due to the proliferation of app stores and the like. Evaluation and research methods have to be adapted to this new context to get the best data and feedback from wide audiences. However, an overview of successful strategies to overcome research challenges inherent to wide deployment is not yet available. App store platform characteristics, devices, reaching target users, new types of evaluation data and dynamic, heterogeneous usage contexts have to be dealt with. This workshop provides a forum for researchers and developers to exchange experiences and strategies for wide distribution of applications. We aim at building an understanding of the opportunities of various distribution channels and obstacles involved in a research context.

Business Models in the Mobile Ecosystem

The mobile ecosystem is constantly changing. The roles of each actor are uncertain and the question how each actor cooperates with each other is of interest of researchers both in academia and industry. In this paper we examine the mobile ecosystem from a business perspective. We used five mobile companies as case studies, which were investigated through interviews and questionnaire surveys. The companies covered different roles in the ecosystem, including network operator, device manufacturer, and application developer. With our empirical data as a starting point, we analyze the revenue streams of different actors in the ecosystem. The results will contribute to an understanding of the business models and dependencies that characterize actors in the current mobile ecosystem.

Mobile exploration of geotagged photographs

Columbus is a mobile application that lets users explore their surroundings through geotagged photographs, presented to them at the location they were taken. By moving around the physical world, the user unlocks photographs and gets to see and experience them in unison with their location. During two consecutive field trials, we investigated how the application was used and experienced and how photographs and locations are explored together. We found that previous experience with the surroundings people was exploring affected how they experienced the localized content. We report on the system’s design and implementation, the trials as well as resulting insights that can be used by other developers of locative media applications.

Configuring Attention in the Multiscreen Living Room

We have conducted a video study of households in Scotland with cohabiting students and young professionals. In this paper we unpack five examples of how mobile devices are used by people watching television. In the examples we explore how screens are used together (a) in a physical ecology, (b) in an embodied way, (c) in an orderly way, and (d) with respect to others. We point out that mobile devices are routinely used to access media that is unconnected and unrelated to media on television, for example for sending and receiving messages, browsing social media, and browsing websites. We suggest that mobile devices are not used to directly enhance television programmes, but to enhance leisure time. We suggest that it is important, when considering mobile devices as second screens, not just to treat these as a design topic, but to pay attention to how they are interactionally integrated into the living room.

Seeing ethnographically: teaching ethnography as part of CSCW

While ethnography is an established part of CSCW research, teaching and learning ethnography presents unique and distinct challenges. This paper discusses a study of fieldwork and analysis amongst a group of students learning ethnography as part of a CSCW & design course. Studying the students’ practices we explore fieldwork as a learning experience, both learning about fieldsites as well as learning the practices of ethnography. During their fieldwork and analysis the students used a wiki to collaborate, sharing their field and analytic notes. From this we draw lessons for how ethnography can be taught as a collaborative analytic process and discuss extensions to the wiki to better support its use for collaborating around fieldnotes. In closing we reflect upon the role of learning ethnography as a practical hands on – rather than theoretical – pursuit.

Ethics, logs and videotape: ethics in large scale user trials and user generated content

As new technologies are appropriated by researchers, the community must come to terms with the evolving ethical responsibilities we have towards participants. This workshop brings together researchers to discuss the ethical issues of running large-scale user trials, and to provide guidance for future research. Trials of the scale of 10s or 100s of thousands of participants offer great potential benefits in terms of attracting users from vastly different geographical and social contexts, but raise significant ethical challenges. The inability to ensure user understanding of the information required to provide informed consent and problems involved in making users aware of the implications of the information being collected all beg the question: how can researchers ethically take advantage of the opportunities these new technologies afford?

Probabilistic Formal Analysis of App Usage to Inform Redesign

Evaluation and redesign of user-intensive mobile applications is challenging because users are often heterogeneous, adopting different patterns of activity, at different times. We set out a process of integrating statistical, longitudinal analysis of actual logged behaviours, formal, probabilistic discrete state models of activity patterns, and hypotheses over those models expressed as probabilistic temporal logic properties to inform redesign. We employ formal methods not to the design of the mobile application, but to characterise the different probabilistic patterns of actual use over various time cuts within a population of users. We define the whole process from identifying questions that give us insight into application usage, to event logging, data abstraction from logs, model inference, temporal logic property formulation, visualisation of results, and interpretation in the context of redesign. We illustrate the process through a real-life case study, which results in a new and principled way for selecting content for an extension to the mobile application.

Services as materials: using mashups for research

Using existing services as development and research materials can greatly reduce development burdens. However, using mashups and existing services has consequences that go beyond the technical realm. We present our experience with developing and promoting a mobile mash-up implemented in the mobile web browser: Spotisquare. Spotisquare is a mash-up of the location-based service Foursquare and music streaming service Spotify. We discuss advantages and tradeoffs of using existing services and the mobile mash-up process, including interaction model choices, as well as validity and representational issues.

2nd workshop on research in the large. using app stores, wide distribution channels and big data in ubicomp research

With the proliferation of app stores and the advancement of mobile devices, research that might have only been tested with a dozen participants in the past can now be released to millions. This offers huge opportunities, but also requires adaptations of existing methods in dealing with large deployments and making sense of large data sets. This workshop provides a forum for researchers to exchange experiences and strategies for wide distribution of applications as well as gathering and analyzing large scale data sets.