Timothy Youngjin Sohn

The design and evaluation of a task-centered battery interface

Battery interfaces provide important feedback about how much time users can continue using their mobile devices. Based on this information, they may develop mental models of the types of activities, tasks, and applications they can use before needing to recharge. Many of todays battery interfaces tend to report energy in coarse granularities or are highly inaccurate. As a result, users may find it difficult to depend on the estimates given. We conducted a survey with 104 participants to understand how users interact with various mobile battery interfaces. Based on the survey results, we designed and prototyped a task-centered battery interface on a mobile device that shows more accurate information about how long individual and combinations of tasks with several applications can be performed. Our pilot study of eight users demonstrated that fine-grained information separated by tasks can help users be more effective with and increase their understanding of their devices battery usage.

Opportunities exist: continuous discovery of places to perform activities

A rich cognitive map of a space can enhance the individuals experience within the space. However, cognitive maps develop gradually through repeated experience; and because of this, on-demand mobile search services (e.g., Google Maps, Yelp) are often used to compensate for missing knowledge. In this work, we developed and evaluated a context-aware place discovery application called Opportunities Exist to assist in the acquisition of spatial knowledge and meaning. The application differs from traditional search in that places are discovered using an activity (e.g., drink coffee, sit in the sun) and the discovery process runs continuously, maintaining a history of places the user can perform her activities as she goes about her day. We conducted a 4-week deployment in two North American cities. The results show that users were able to discover new places to perform their activities in familiar spaces and learned to associate new activities with familiar places. In addition, participants leveraged the application to perform activities opportunistically, and used continuous place discovery as an opportunistic reminder of routines they wanted to break out of or resume.

Planning, apps, and the high-end smartphone: exploring the landscape of modern cross-device reaccess

The rapid growth of mobile devices has made it challenging for users to maintain a consistent digital history among all their personal devices. Even with a variety of cloud computing solutions, users continue to redo web searches and reaccess web content that they already interacted with on another device. This paper presents insights into the cross-device reaccess habits of 15 smart-phone users. We studied how they reaccessed content between their computer and smartphone through a combination of data logging, a screenshot-based diary study, and user interviews. From 1276 cross-device reaccess events we found that users reaccess content between their phone and computer with comparable frequency, and that users rarely planned ahead for their reaccess needs. Based on our findings, we present opportunities for building future mobile systems to support the unplanned activities and content reaccess needs of mobile users.

Myngle: unifying and filtering web content for unplanned access between multiple personal devices

Users often engage in tasks that span multiple personal devices. Although many current solutions exist to provide ubiquitous access to ones data, users continue to struggle with cross-device tasks. These solutions often require them to plan ahead for their information needs. In this paper, we present Myngle, a device-agnostic system that lets users quickly find the information they are looking for from previously visited web pages without having to plan ahead. Myngle provides a unified web history from multiple personal devices, and allows users to filter their history based on high-level categories influenced by common mobile information need categories (e.g., address, phone number). We evaluated Myngle with 32 users and found that our category-based method of filtering eases the burden of continuing cross-device tasks.

Enabling cross-device interaction with web history

Internet-enabled personal devices are growing in number. As people own and use more devices, sharing information between devices becomes increasingly important. Web browsing is one of the most common tasks, thus sharing web history is a first step in supporting cross-device interaction. Current methods of sharing web history involve manual, cumbersome methods. This paper explores a system to automatically synchronize web information among a users personal devices, and optimize the interface to support mobile users. We describe a system that enables users to quickly find directions on their mobile phone based on past web searches, and seamlessly share favorite web pages between their personal devices.

At your service: using butlers as a model to overcome the mobile attention deficit

Advances in mobile phones and cellular network capabilities have enabled many opportunities for information access on the move. These capabilities provide instant access for the mobile user, but have exacerbated the problem of interaction in a mobile context. Mobile users are often engaged in another task that makes it difficult for them to filter and interact with their mobile device at the same time. Mobile multitasking creates an attention deficit for the user. This paper proposes using butlers as a model to overcome this problem by offloading the burden of interaction from the user to the device. We describe how a suite of butlers can opportunistically and proactively offer information to the user in the moment, allowing mobile users to stay focused on their task at hand.

Supporting unplanned activities through cross-device interaction

People interact with numerous personal devices on a daily basis. Sharing content among these devices is often done depending on the device capabilities and context of use; following turn-by-turn directions is more appropriate when mobile. Although several solutions exist to share content among ones devices, these solutions rely on the user planning ahead for the data he may need on another device. In this paper, we describe a system that addresses the unplanned activities, by automatically extracting addresses and points of interest that users view in their web browser and making those readily available through an in-car interface.

Auditory priming for upcoming events

Psychologically preparing for upcoming events can be a difficult task, particularly when switching social contexts, e.g., from office work to a family event. To help with such transitions, the audio priming system uses pre-recorded audio messages to psychologically prepare a person for an upcoming event. In this system, audio priming is being used to prepare a persons state of mind to improve ones sociability in the upcoming social context.