Each university has its own range of grades, so check with your university’s exam office and make sure you discuss this with your supervisor, who normally also plays a key role in helping you apply the examiners’ suggestions for changes and in checking the corrections where applicable. From a general point of view, it is nevertheless possible to identify the following scale:
1. Award of PhD: if both your thesis and your viva are entirely satisfying (or if your thesis requires minor amendments (e.g.: typos) which can be carried out in one day, before your thesis is deposited in the Library).
2. Pass with minor amendments: deferment of the award until specific amendments will have been implemented within a set period of time (e.g.: at the University of London within three months).
3. Referral: deferment of the award for a period that can vary from six to eighteen months: if your thesis needs substantial modifications. In this case you will be sent a written statement - listing precisely all amendments required and fixing a new deadline for its re-submission within a couple of weeks. You may also be asked to take a new oral examination in front of the same board.
4. Downgrading to the award of M.Phil: if your thesis does not meet the requirements to be awarded a PhD (e.g.: it lacks originality), but it deserves a postgraduate degree for its critical investigation and evaluation of the existing body of knowledge.
5. Deferment of the award of M.Phil for a period that can vary from six to twelve months: if your thesis needs substantial modifications even to be awarded an M.Phil
6. No award of any kind: if your thesis does not meet the requirements to be awarded either a PhD or an M.Phil, and its general structure does not seem to allow for any effective amendments.
Appeal regulations vary from University to University. Below you can find as an example the guidelines of the University of London as regards reasons for appealing against the outcome of your examination and the evidence you will be asked to provide. If you think that the decision of the examining board results from improper conduct on the part of the examiners, you may be able to appeal on the following grounds:
Illness: for example, a certificate or letter from a medical practitioner setting out the condition and its symptoms and effects, together with a statement from the appellant describing the condition and the difficulties he/she experienced. The Committee will be particularly concerned to establish that the illness affected the appellant's performance on the date of the oral examination.
Prejudice - bias or inadequate assessment: for example, a statement by the appellant, or comments emanating from a third party, recording comments or remarks made by the examiners, whether at the oral examination or otherwise, disclosing prejudice or bias or suggesting inadequate assessment. The comments, remarks or facts which in the appellant's view indicate prejudice, bias or inadequate assessment, must be set out fully and clearly.
Procedural irregularities: the appellant must set out clearly and fully what in his/her view are the irregularities or error, how and when they occurred and the person responsible, to the extent that this is known, and how it may have or did affect the outcome.
Please consider that appeal procedures are a lengthy process. If you want to appeal you will be required to submit a written report to the relevant authorities. You will have to prepare sound evidence for your reasons of questioning the examination results when you appear before the appeal committee. Moreover, it is important to understand that you are not allowed to call the examiner's academic judgemment into question. Appeals are not conducted in order to re-assess the scholarly quality of your dissertation. According to the University of London regulations
Again it is sensible to ask your supervisor for support and help. If, on the contrary, it is your supervisor about whom you are complaining, you can refer to the Head of your Department or directly to the office of your university that deals with postgraduate matters (e.g.: graduate schools, offices and boards).