We address a problem examined by sociologists of 'Big Science': the co
ordination of individuals on large-scale projects - in this case, indu
strial technology projects. We consider co-ordination to be a problem
of social order which can be addressed through ethnomethodology's unde
rstanding of accountable action. We propose that the technology produc
ers studied attend to the problem of the coordination of their work in
the design of their actions and interactions as organizationally acco
untable. We subsequently examine the methodical practices through whic
h they interrelate their actions within an organizational context, and
thus organize the co-ordination of their technological work and the p
roduction of their technology outcomes.