As the result of recent changes in England and Wales, higher education institutions are expected to enter into formal partnership agreements with schools for the provision of initial teacher education (ITE). Students are required to spend a considerable proportion of their course in the classroom under the supervision of teachers acting as mentors whose role is to help them acquire mastery of a number of 'standards' or competencies, nine of which are concerned with the ability to assess pupils' achievements. Responses received in questionnaires from a sample of over 100 mentors and some 200 students suggest that problems have been encountered in this system of ITE as far as acquisition of the assessment Standards is concerned. Not all schools have been able to provide the necessary range of experience and de ciencies can be identi ed in mentoring practice. In the light of these ndings, some suggestions are made for improving the quality of school-based ITE, and a model of mentoring is offered which seeks both to prepare student teachers to assess their pupils' progress effectively and to help them re ect upon wider professional issues.