The ability of people with dementia to participate in social interactions is progressively undermined by the illness. This is due in part to memory and speech production difficulties but also to changes in behaviour that can deter potential interaction partners. Therapeutically, reminiscence is a popular medium in dementia care for promoting conversation and positive interactions. By tapping into relatively intact long-term memory, reminiscence encourages people with dementia to recall and share memories from their past. Computer technology provides the opportunity to present a large multimedia database of stimuli to use in reminiscence. CIRCA is an interactive hypermedia-based system designed for people with dementia to facilitate and support conversation and social interactions. The system contains a large database of media presented via a touch screen to act as a prompt for interactions between people with dementia and caregivers. We evaluated the usefulness of CIRCA by comparing it with one-to-one reminiscence sessions conducted using traditional reminiscence stimuli. Unlike traditional reminiscence CIRCA gives people with dementia the opportunity to direct interactions and make choices. This enables them to regain their status as interaction partners.