Different measures of student knowledge and achievement are abundant in continental Europe as well as in Sweden. Many are the nations involved in comparative efforts like PISA, TIMMS, etc. These large-scale evaluative processes are generally linked to national and international political debates, policy-making and ideas of competition. However, student assessment also serves other purposes, like selection to higher levels in the education system, as is the case in Sweden. Independent of purposes, student assessment is not a neutral activity vis-à-vis the students - assessment affects them. More subtle effects of assessment are the ways the every day practice of assessment mould the individual students, their behaviour, their perception of learning, curricular content, and self- understanding. As a first step in a larger project, this paper reports results from a minor exploratory classroom study of student assessment. The aim of the study was to generate information about assessment in action in educational practice, i.e. in classroom settings. The information gained is to be used to develop an observation instrument that can be used for more focused classroom observations concerning every-day assessment practices. The study was carried out in two student groups in grade 1 and 5 during 1-2 days in each group. A method of observations documented by ongoing written accounts of classroom activities was used. In the analysis attention was mainly paid to the teachers' actions and speech activities. A quite simple scheme of concepts was developed, in which the two broad categories "What is assessed by the teacher?" and "How is it assessed?" form the basis. It is nevertheless argued that this scheme may work fairly well as a data collection devise in further studies on assessment perceived as the moulding or governance of individuals. This is perhaps particularly the case when there is a lack of resources to carry out extended (and/or video-taped) classroom observations.