In recent decades the doctorate and its purposes have undergone fundamental change. The scholarly model has evolved from one of 'apprentice' to independent, supported learner and the doctoral training process has been revolutionised; many candidates now experience cohort-based, structured research. The UK's final PhD examination, however, has changed little in response and as a result has been called into question: does the current model -- thesis evaluation followed by a viva voce examination -- adequately assess the candidate, their achievements and their potential? This article includes data from a larger study that included live observations of viva examinations and interviews with candidates, supervisors and examiners. In the article, we explore the developments that have transformed the UK PhD from an elite 'licence to practise' for a minority to a mainstream qualification increasingly used to enhance career prospects. We consider the fitness for purpose of the examination by analysing the attributes assessed through the thesis and the viva. The article concludes by questioning whether the examination process enables examiners to communicate the attributes on which judgements are based: the candidate's ability to conduct research independently, their professional and personal characteristics, and their potential career prospects.