WeBIUM 2025: 2nd Workshop on Wearable Devices and Brain-Computer Interfaces for User Modelling

Wearable Devices (WDs), such as smartwatches and fitness trackers, continuously produce extensive data streams that reveal valuable information about physiological states, activity patterns, and user interactions. These devices enable the construction of advanced user models, offering dynamic insights into personal routines, health trends, and behavioural tendencies. Meanwhile, Brain-Computer Interfaces (BCIs) emerge as a transformative technology by capturing neural activity to provide unprecedented access to cognitive and emotional states. However, BCIs are not conventionally classified as wearables; the latest technological advancements have reduced their size to resemble everyday accessories like earphones, suggesting their potential integration into wearable formats in the near future.Despite the promise of these technologies, the full exploitation of their data for user modelling and personalization-such as optimizing activities like media consumption or interaction design-remains underexplored. The convergence of WDs and BCIs opens up new avenues for understanding the complexity of human behaviour and preferences, and this potential is amplified by the integration of Large Language Models (LLMs). By synthesizing and interpreting multimodal datasets, LLMs can better understand the intricate interplay between physiological, cognitive, and behavioural signals, ultimately enriching user modelling processes.Following the success of the first edition, this workshop seeks to delve into the deep impact of combining data from wearable devices, neural interfaces, and advanced machine learning models. Participants will explore the opportunities and challenges that arise in this innovative context, examining how these technologies can be harnessed to enhance the granularity and accuracy of user models. The discussions will also address practical implications, such as ethical considerations and the necessity of privacy-Aware approaches when dealing with highly sensitive physiological and neural data.Through collaborative exchanges, the initiative aspires to chart new directions in the field, fostering novel research trajectories and interdisciplinary partnerships. The interplay of WDs, BCIs, and LLMs can redefine user modelling by creating systems that dynamically adapt to individual needs and behaviours, paving the way for transformative advancements in personalized experiences. By drawing on cutting-edge research and practical expertise, the workshop aims to inspire innovative solutions that capitalize on these emerging synergies, advancing the boundaries of what is possible in user modelling and adaptive systems. © 2025 Copyright held by the owner/author(s).