Description: Restructuring processes within contemporary (western) societies carries new demands and pressures on well-fare state professionals. Increasing figures of work-overloads and burn-outs picture one, important, dimension of work situations that could be related to an overall destabilisation and extension of the work processes themselves. Teachers' work is for example to a larger extent carried out outside the classroom; by means of joint planning and evaluative activities as well as documentation of such work. The health care workforce has undergone dramatic infrastructural changes. Nurses' work is increasingly carried out in work teams including assessment activities, evaluation and documentation. Extensions such as these can be expected to lead not only to contractions among assignments, expectations and demands, but also to new configuration of epistemic cultures among professions and professional systems. In this paper, we address questions of knowledge "at work" within the professional systems of teachers and nurses. We will lay to the fore the complex features of these professional machineries, their technologies, routines and diversifying objectives and give some examples of the transformative dynamics within the daily life of the two professions. The study is based on the comparative survey presented above but informed by ethnographic studies and life histories.