In order to explore the current views of the interface community and to develop an understanding of the present state of play, research specialisation (from education research) which studies knowledge development, has been applied to research variation in the community's ways of experiencing the 'interface' as a phenomenon in composite materials. Ten leaders of the field were interviewed and the transcripts of those interviews collated and analysed. Four dimensions of variation in the ways researchers view the interface were uncovered. It is found that there is not even general agreement as to whether the interface is: an object, which can be measured, or an illusive concept. The resulting 'outcome space' or collective consciousness may lead to a broader understanding of the issues involved. (C) 2001 Elsevier Science Ltd. All rights reserved.