This paper explores ways in which examiners, supervisors and others interpret the concept of "originality" when evaluating candidates' achievements in the final Ph.D. examination. It is based on institutional responses to a question in a 2006 discussion paper on doctoral assessment about how universities define originality for the purpose of Ph.D. assessment and what other criteria are used to guide examiners in making judgements in the final examination. The paper also includes emerging findings from the first stages of data generation for a Ph.D. study about how examiners assess the Ph.D. This study involves viva observations and interviews with candidates, examiners, supervisors and independent chairs of vivas. Most participants, irrespective of role, discipline or field, confirmed that "originality" or "a contribution to knowledge" is required for a candidate to pass the Ph.D. examination, and that this criterion is interpreted in a subject-specific context by examiners. The studies suggest that the discipline or field in which the candidate's topic is situated influences the examiners' interpretation of "originality" and their expectations of the candidate. However, "originality" is not the only criterion for the Ph.D., and students are also required to demonstrate other achievements to pass the doctorate. The studies show that there is some degree of consistency among examiners in the general criteria used to evaluate the candidate's thesis and performance in the viva. These findings are discussed in the light of the literature.