Ninety-seven percent of people with dementia develop at least one behavioral or psychological symptom, such as agitation or depression, within five years. To address Behavioral and Psychological Symptoms of Dementia (BPSD), researchers are exploring personalized management, leveraging assistive technologies that collect both qualitative data from care teams and quantitative data from Internet of Things (IoT). However, few studies examine how blending these data types could help care teams better understand and support residents in nursing homes. Through a Research through Design approach, a prototype was developed with care teams to combine, visualize, and analyze both data types, guiding personalized BPSD management. Key findings show that data needs vary by resident, qualitative and quantitative insights enhance each other, quick and flexible data collection is essential, and targeted prompts encourage data review in daily routines—offering new insights for improved dementia care.