Managing social batteries is crucial in highly interactive environments such as open-plan offices. To support both the internal self-management of one's own social battery and the external coordination of interactions with others, we designed Sotate, a device that visualizes social batteries. Sotate uses a gauge-style LED display to represent a user's social battery level and physical placement to indicate when the user is engaged in recharging activities. Our three-week field study with four groups revealed that participants used social battery representations not only to reflect their internal states, but also to intentionally express non-literal states to manage external communication. We also found that explicitly marking the beginning and end of recharging made recharging activities more deliberate and reflective, and that colleagues relied on simple, immediately interpretable cues rather than precise numerical values when coordinating interactions. These results highlight design considerations for systems that support the management of internal states associated with social interaction.

While the rapid exchange of messages in instant messaging (IM) is useful for maintaining convenient and continuous communication, it can simultaneously diminish recipients’ opportunities to reflect on and emotionally engage with individual messages. This paper introduces Adilet, a system that represents the process of composing and receiving delayed messages through a physical device, designed to enhance message awareness, perceived value, and reflective engagement. Adilet allows users to ensure the status of writing, sending, and receiving messages and approximate total writing time. A field study with four groups of two close partners demonstrated that Adilet improved message quality by increasing participants' awareness on both writing and reception. Furthermore, consistent awareness of message presence and clues about message content enhanced anticipation. Our findings suggest further implications for designing communication systems that support deeper and more valuable emotional exchange by improving message value and recognition in close relationships.

In open-plan offices, face-to-face (F2F) interruptions frequently occur to facilitate collaboration and cooperation with colleagues. We designed Pati & Bellio to support the coordination of F2F interruptions in open-plan offices. Pati is a partition-style personal device that visualizes availability for F2F interruptions and Bellio is a shared interface that allows users to send notifications to their colleagues from a distance. Our three-week in field study with four groups of participants reveals that examining the process of F2F interruptions helps determine the importance of the interruption, and the physical distance provided by Pati and Bellio naturally allowed time to prepare for conversations. We also identified how the visualized availability is considered after an interruption begins. Our findings imply considerations in designing systems to support coordinating social interaction in work environments.

Accumulating a life history is a valuable resource for understanding self and reflecting on personal historical experience, which could be developed through diary writing. To facilitate the recording of past events in a diary, we designed and implemented Rebulb, a system that enables users to engage with reflective questions about proud moments and document memories evoked for accumulating one's life history. Our four-month field study with three participants showed that users intentionally and spontaneously recalled vague and wide memories during their daily activity and then concretized these memories by writing them down in a journal. The study also revealed that regardless of whether the memories were positive or negative, the current state of the user played a crucial role in how these memories were processed and reflected upon. Our finding imply consideration in designing a tool for supporting the recall and documentation of past experiences.

Model-agnostic explanation methods are essential for interpreting machine learning models, but suffer from prohibitive computational costs that scale with the number of baselines. Existing acceleration approaches either lack a theoretical base or provide no principled guidance for baseline selection. To address this gap, we present ABSQR (Amortized Baseline Selection via Rank-Revealing QR). This framework exploits the low-rank structure of value matrices to accelerate multi-baseline attribution methods. Our approach combines deterministic baseline selection via SVD-guided QR decomposition with an amortized inference mechanism that utilizes cluster-based retrieval. We reduce computational complexity from O (m • 2d) to O (k • 2d), where k ≪ m. Experiments demonstrate that ABSQR achieves a 91.2% agreement rate with full baseline methods while providing 8.5× speedup across diverse datasets. As the first acceleration approach that preserves explanation error guarantees under computational speedup, ABSQR makes the practical deployment of interpretable AI systems feasible at scale.

The remote communication within intimate groups can be challenging due to lack of or excessive of non-verbal messages, which lack physicality. In this paper, we introduce Stubbi, a device designed to enhance remote text and voice communication in small intimate groups by enabling the exchange of simple physical movements. Each group member is equipped with Stubbi, which consists of three stubs that represent each person and enable the expression of physical movements through height changes and rotation. Our in-lab study involving six groups of three friends revealed that Stubbi effectively maintained the flow of IM conversations by increasing attentiveness and responsiveness. Additionally, in group voice calls, the exchange of personified messages through physical movements of the stubs assisted group interactions, such as turn-taking. Our findings suggest faurther implications for designing interactive systems that can support improved remote communication by seamlessly connecting IM and voice call conversations for small intimate groups.

Being a little more careful about the sound that people produce is difficult in shared houses because individuals can generate several unintended living noises and sounds. We designed Tunee to help each housemate better understand the others’ context and desired noise-level. It is an interactive speaker that allows people to share noise-level preferences through the position change of nodes. Our three-week in-field study with four groups of participants revealed that expressing noise-level preference through nodes reduced the burden of verbally delivering issues about the trivial noises of everyday life, and the intentions of the lowered preference were referred to and deemed significant. We also identified how participants figured out what behavior was acceptable for others according to each noise-level. Our findings imply considerations in designing interfaces to support coordinating behaviors and awareness of social contexts in shared spaces.

When expressing personal data on the displays of personal IoT devices, it is important to be intuitively aware of privacy settings and perform ready-to-hand interactions to respond appropriately to various situations occurring in shared spaces. In this paper, we developed Posit, an interactive calendar in which the disclosure level of schedule content can be changed in three stages according to the object's placement by the user. The results of our three-week in-field study with six participants revealed that Posit's interaction was considered to be a simple way of hiding personal schedules quickly, and we could identify the roles of the positional messages in determining the others’ gazes on displays. Additionally, we confirmed that social relationships and trust between colleagues affect the use of Posit. Our findings imply new opportunities in designing interactions for the management of personal privacy by applying physical state-changing interaction and understanding social factors in shared spaces.