Order and disorder in conversation: encounters with dementia of the Alzheimer's type.

After a brief introduction to Dementia of the Alzheimer's Type (DAT), its behavioral diagnostic symptom complex and a summary of communicative implications, we present data from two conversations involving participants with and without DAT. We discuss the concept of "order" in conversation, and the central importance of interactional monitoring. Conversational success and problems in interactions with persons with DAT are seen as emergent from situationally embedded conversations in the presence of cognitive and linguistic impairments on the part of the person with DAT, and of contextually situated communicative impairment resulting therefrom.