Defining Reality in Dementia VR: Stakeholder Perspectives on Ecological Validity for Functional Activity Training

Virtual reality (VR) is increasingly used in dementia care, yet most applications focus on recreation or cognitive stimulation rather than supporting the everyday activities that matter for independent living. To understand what makes VR practice feel realistic and useful for people with dementia (PwD), we conducted semi-structured interviews with PwD, caregivers, and therapists using visual probes grounded in daily living contexts. We examine how stakeholders define realism and usefulness in VR-based support for instrumental activities of daily living (IADLs) and how these judgments relate to the concept of ecological validity. Our findings show that realistic IADL-based VR is characterized by environments and task flows that align with the cognitive and functional demands of real-world activities, while useful VR evokes behavior that meaningfully reflects everyday performance and supports rehabilitation practice. We translate these insights into design implications for at-home IADL-focused VR systems that emphasize functional fidelity, adaptability, and collaborative use, grounding real-world relevance in the lived routines and caregiving ecosystems of PwD.