This paper responds to the vision of a new assessment culture, which will be a meaningful integration of teaching, learning and assessment. It reviews the advice in the literature about assessment, and from there identifies principles for the assessment of the development of higher level abilities in various domains. It envisages the student as an active participant in the development of criteria and standards, and their consequent use in the making of judgements. The suggested principles are tested out on a recent conventional experience that brought the writers together as tutor and student, and on their subsequently proposed generic model.