Attendant-resident interaction and adaptive behaviour of residents were examined in a typical villa for low­ ability mentally retarded in a New Zealand residential institution. A series of three studies were undertaken. Initially a survey was made of the adaptive behavioural levels of residents (as rated by attendants) and the frequency of social interaction in the dayroom (Study 1). A low frequency of attendant-resident interaction was expected, and an attempt was made to communicate-the developmental potential of residents to attendants. A precision training programme designed to facilitate self-care behaviour in a group of residents was instituted and its effects examined. At the same time a Hawthorne group received an unstructured 'activation' programme, and a control group remained in the dayroom and continued their usual daily programme. The experiment continued over an eight week period, after which observations were again made of dayroom social interaction and of the extent of change in attendants' and residents' behaviour. Results indicated that although severely and profoundly retarded institutional residents displayed an impoverished behavioural repertoire they were capable of learning self-care skills when taught via precision teaching methods. At the same time, the transfer effects from such training seemed highly specific and there was an indication that some form of activity or training programme helped offset the development of withdrawal behaviour in residents. Finally, although the adaptive behaviour of long-term institutionalised residents was improved and attendants were shown to be aware of such improvement, their awareness had no apparent influence on the extremely low level of attendant-resident interaction observed in the dayroom area. The results were discussed in terms of various institutional factors which either instead of, or in addition to the attendants 'perception of residents ability' could have been responsible for the low level of attendant-resident­ interaction and for the lack of change in the attendants' behaviour.