Brian Balmer and Norma Morris present their research on (women) volunteers’ experience of participating in experimental medical research, in this case the testing of a novel breast imaging technology likely to have potential for the diagnosis of breast cancer. The data collected from interviews and participant observations highlighted the often overlooked social challenges of participation in an experiment, including how volunteers’ concerns about their ‘performance’ outweighed those surrounding risk or physical discomfort. Morris and Balmer also elaborate on their finding that volunteers were commonly active, enthused, and resourceful, a conclusion that chimes better with current ideas of doctor-patient partnerships and active consumer participation in research rather than the commonly encountered construction of the vulnerable and passive ‘subject’ that informs current ethical and regulatory structures. Although Morris and Balmer do not claim that their research setting was representative, as volunteers’ aspirations will vary according to circumstances, they suggest that public policies for clinical research governance might usefully give more attention to the social and interactive dimensions of participation that are critical to making a satisfactory experience for volunteers and successful research outcomes.