Investigating Context-Aware Collaborative Text Entry on Smartphones using Large Language Models

Text entry is a fundamental and ubiquitous task, but users often face challenges such as situational impairments or difficulties in sentence formulation.Motivated by this, we explore the potential of large language models (LLMs) to assist with text entry in realworld contexts.We propose a collaborative smartphone-based text entry system, CATIA, that leverages LLMs to provide text suggestions based on contextual factors, including screen content, time, location, activity, and more.In a 7-day in-the-wild study with 36 participants, the system offered appropriate text suggestions in over 80% of cases.Users exhibited different collaborative behaviors depending on whether they were composing text for interpersonal communication or information services.Additionally, the relevance