Lack of clarity about assessment criteria and standards is a source of anxiety for many first-year university students. The Developing Understanding of Assessment for Learning (DUAL) programme was designed as a staged approach to gradually familiarise students with expectations, and to provide opportunities for the development of the skills required to successfully complete assessment tasks. This paper investigated the students' perceptions of the first two components of the DUAL programme, which assist first-year biology students to engage with stated assessment criteria and standards in order to develop their capacity to make judgements about scientific report exemplars, their peers' scientific reports and ultimately their own. The study found strong evidence (96% of responses) that the marking and discussion of exemplar reports with peers and demonstrators clarified expectations of scientific report writing. A key feature of this element of DUAL was the opportunity for structured discussion about assessment criteria and standards between peers and markers (demonstrators). During these discussions, students can clarify explicit statements and develop a tacit knowledge base to enhance their ability to judge the quality of others' work and their own. The peer review exercise (the second element of DUAL) was not rated as highly, with 65% of students finding the process helpful for improving their report. The negative reactions by a sizeable minority of students highlight the need to clearly communicate the expectations and benefits of peer review, with a focus on how the process of giving feedback to peers might benefit a student as much as receiving feedback on their own report.