Doctoral studies are carried out by science graduates, medical students combining clinical training with the PhD, and clinically qualified doctors undertaking scientific training. Research covers the whole spectrum of medical science from basic biology to clinical therapies. Along with the specific research training provided in the laboratory in which they work, students receive further training within the department in the form of graduate workshops concentrating on research techniques, research seminars both on the Addenbrooke's site and elsewhere in the University, and graduate student seminars dealing with generic skills such as intellectual property rights, writing a thesis or paper, and entrepreneurship. PhD students are required to submit a dissertation of no more than 60,000 words within a maximum of 4 years of study. This is examined at a viva by two examiners, one Internal and one External. PhD students are required to undergo formal assessment (by written report and viva) at the end of their first year. If successful, the student moves from being 'probationary' to being registered for the PhD and can proceed with their project.