We assessed the use of a microswitch cluster (i.e. a combination of two micro-switches) plus contingent stimulation for promoting adaptive responding and reducing aberrant behaviour in a woman with profound developmental disabilities. The woman was initially taught an adaptive hand response that activated a pressure microswitch and produced preferred stimuli. Subsequently, her hand response led to preferred stimuli only if it occurred free from face hiding (i.e. aberrant behaviour detected through a mercury microswitch). The study also included a 3-month post-intervention and generalization check, and a social validation assessment. Data showed that the woman increased her adaptive responding, learned to perform this responding largely free from aberrant behaviour, and maintained and generalized the new performance across settings. Forty-five psychology students provided positive social validation of the woman's new performance and the use of microswitch-cluster technology.