Increased understanding of the link between learning and assessment combined with a shift to view learning as more a social than an individual process have contributed to an appreciation of the role that classroom assessment can play in enhancing student learning and achievement. Nonetheless, very little is known about student experience of classroom assessment, including their experience of formative assessment as assessment for learning. This paper draws on data generated through student interviews and classroom observations to present student perceptions of their assessment in science lessons. The argument in the paper is grounded in and evolved out the use of a sociocultural perspective to make sense of the student data. Student commentary indicated that assessment shaped what it meant to be a student and to learn and know science.