This paper presents some of the findings of a naturalistic study of a first year university biology laboratory. We report on the affective outcomes for a field trip and a practical exercise that incorporated innovations aimed at increasing the scientific realism and students' responsibility in the learning process. Concern with assessment procedures and a perceived lack of teaching support dominated outcomes for students. Feelings of confusion, lack of satisfaction and hostility were evoked. Recognition of the need to foster greater student input into the learning process is commended, but this paper raises issues about the strategies utilised.