Abstract:Objectives: Despite an abundance of research acknowledging the value of interactive occupation and social engagement for older people, and the limits to these imposed by many residential settings, there is a lack of research which measures and analyzes these concepts. This research provides a method for measuring, analysing and monitoring interactive occupation and social engagement levels of residents in a secure residential setting for older people with mental health problems and dementia. It proposes suggestions for changes to improve the well-being of residents in residential settings. Method: In this case study design, the Assessment Tool for Occupational and Social Engagement (ATOSE) provided a 'whole room' time sampling technique to observe resident and staff interactive occupation and social engagement within the communal sitting room over a five-week period. Researchers made contemporaneous notes to supplement the ATOSE data and to contextualise the observations. Results: Residents in the sitting room were passive, sedentary, and unengaged for 82.73% of their time. Staff, who were busy and active 98.84% of their time in the sitting room, spent 43.39% of this time in activities which did not directly engage the residents. The physical, social and occupational environments did not support interactive occupation or social engagement. Conclusions: The ATOSE assessment tool, in combination with narrative data, provides a clear measurement and analysis of interactive occupation and social engagement in this and other residential settings. Suggestions for change include a focus on the physical, social, occupational, and sensory environments and the culture of care throughout the organization.