It may be of interest to students to understand how the Tripos Examinations are set and marked:
- The Physics Examiners, although they are ordinarily staff of the Department, are formally independent of it, and are appointed by the Faculty Board. In Part II and Part III there are External Examiners appointed from other Universities who ensure that uniform standards are maintained across the country. In Part I and Part II lecturers are consulted by the Examiners, but are not directly responsible for setting the questions. In Part III the lecturers are all appointed as Assessors; the questions are set jointly by the Assessors and the Examiners, and marked by the Assessors. The formal independence of the examiners from the Department derives from the wording of University regulations, but in practice where it is clearly desirable for consultation to take place between examiners and the Department or its committees this does occur.
- The Examiners put an enormous effort into ensuring that the examination is a fair test of the course. All questions are discussed with the lecturers but the final decisions as to content rest with the examiners. Model answers and detailed mark schemes are prepared for all questions, which in Part II and Part III are reviewed by the External Examiners. All questions are also checked independently of the setter, lecturer and the model answer, and finally reviewed in detail by all Examiners. For some questions, an outline mark scheme appears on the examination paper for the guidance of candidates.
- Various checks are made during the marking process, for instance, to ensure that every piece of work has been marked, and to check every mark addition and every mark transfer. A percentage of papers chosen at random is remarked by a different examiner, to make sure that the mark scheme is being followed correctly. Except for some coursework, the markers do not know the identities of the candidates. Nothing in the physics course is marked directly by machine. Marks are however transferred and scaled by computer, but using algorithms designed to protect against error. For instance, marks are only transferred with the candidate number attached, to guard against allocating marks to the wrong candidate.
- The Examiners employ statistical methods to look for bias which might affect the fairness of the marking, and where considered appropriate, to correct it by mark scaling, for instance, after comparing the mark distributions of different questions on the same paper. This process of moderation is particularly important where several different markers are involved (as in Part II Research Reviews and Part III Projects), or where different types of work are alternatives (as in comparing the distributions of marks in E1 and E2 with TP1 and TP2 in Pt II). For practicals (Head-of-Class reports, notebooks etc) in Parts IA and IB, the marks are moderated by each Head of Class and then by the overall Head of Class.
- The Examiners are given general criteria for classing (see Classing Criteria, for Part I, and Parts II and III) but thereafter use their own judgement. However, in Part I they are given guidance on the proportions of candidates likely to fall within a given class, and in Part II and Part III they are given statistical information about the overall performance of the same group of students in earlier parts of the Tripos ("cohort tracking"). Groups of candidates near the various class borderlines are considered in detail.
- In July each year, the whole Department meets to consider the Examinations. The work of each body of Examiners is reviewed by one or more independent critics, and recommendations for change are made where necessary.