Examiner proof-reading master thesis before submission. Is this allowed?
Whether it is allowed depends on the specific regulations of your university, but your advisor proofreading your thesis and offering suggestions is quite common. I would consider not having a proofreading round to be lazy on the part of the advisor.
Keep in mind that the examiner can still have the initial reading influence the grade. Somebody who submits a perfect thesis that requires no corrections would usually get a higher grade than somebody who submits the same thesis after receiving detailed comments on how to improve it. The proofreading is part of the teaching process, and how well you implement the suggestions is part of the assessment.
What do you think is better from a didactical perspective?
Telling a student that they got a barely-passing grade because X and Y need to be improved
Telling a student that they could improve X and Y by doing Z, and having them do that before assigning a final grade
Clearly, the student will learn much more from option (2).
Let me start with a quote from Good scientific practice for scientific qualification reports and theses in physics (German version). These are recommendations are published by the conference of German physics departments, whose prime purpose is to coordinate teaching and thesis standards. This document is specific to physics (and makes this point itself) but after all I heard, it holds at least for all the physical sciences, mathematics, and computer science:
At the same time, in physics it is part of the scientific discourse that parts of the qualification report or thesis are presented in advance to another person, e.g. to the supervisor, for critical commentary. Such commentary can refer to the interpretation of the scientific results themselves, the organization of the subject matter, or the chain of arguments within the report or thesis. For doctoral theses, the commentary should rather have the character of a collegial feedback. For reports and theses within undergraduate or master studies, it is also a duty of the supervisor to aid the student in developing the competences necessary for writing such a report or thesis. Within the development of the study program, this aspect should play a lesser role.
In my experience and from what I gathered from colleagues, the rationale for this is:
Part of the purposes of a thesis project (and studying in general) is that the student learns how to present their own work in writing. Providing constructive criticism on the thesis before submitting and having the student implement this (often in multiple iterations) is the best way to nurture this, as the student is forced to revisit their own writing and engage with the criticism. Critical comments on the final product do not achieve this, as the student has no motivation to revisit their thesis and doesn’t get the fruit of their work examined.
I have never encountered any student (including myself) who had sufficient writing skills to write a paper before finishing their master’s thesis under proper supervision (i.e., with criticism before submission). Usually the pre-supervision writing skills were abysmal by any standard and then were considerably improved during the thesis-writing process.
We train the student for real writing, whether in academia (papers, grant applications, etc.) or in industry settings. And it is rare and inadvisable to write anything important in a vacuum. One always has co-authors and colleagues or similar whom one can and should solicit for constructive feedback. Even for the papers I wrote as a single author, I solicited the feedback from colleagues and supervisors before submitting them. By contrast, I did peer-review some papers where I was very likely the first person to read them and they often had severe shortcomings in writing. Thus having feedback from the supervisor is a more realistic writing conditions and also trains the valuable skill of handling feedback on one’s writing.
The supervisor (usually) doesn’t dictate sentences to the student, but just shows them what is wrong and provides guidance on how to fix these issues. Thus the condition that everything written is the student’s own work is not violated.
In particular for bachelor’s and master’s projects, the stated purpose is that the student performs a scientific project under supervision and I see no reason to exclude the writing process from this. With other words, applying constructive criticism from your supervisor to your thesis is part of the project and the grade captures how well this was done. (Thus there is no paradox of “proof-reading something for one’s own examination” does not really arise.)
One hardly ever compares theses under different supervisors with respect to their grading and even if one does, the topics may be considerably different in how challenging it is to write about them. Thus the unfairness issue simply does not arise. Moreover, a supervisor has far stronger means to give an unfair advantage to their supervisees.
Finally, some further remarks:
I strongly urge students I supervise to hand in the very first page as soon as they have written it. This way I avoid that bad practices become a habit and their further writing already has a better quality before I first see it. For this reason, I think any good supervision should engage with the thesis long before it is complete.
I disagree with the idea that the initial thesis (before critical comments) should influence the grade. As already stated, one of the points of the thesis project is that the student learns writing about their own scientific work and they have no chance to acquire this skill elsewhere (except for previous theses and similar). A student who considerably improves their writing during the supervision process should be rewarded. Students who already have the skill are likely to have it not due to their own ingenuity but because they enjoyed a proper thesis supervision before. Moreover, implementing constructive criticism is part of the skill we want to teach and thus the grading should reflect it. Finally, there is no clear separation between before and after supervision in case of a good supervision (see the previous point).
That being said, in my experience there is a strong correlation between the quality of the initial writing and the final result, with the latter being considerably better. The main exceptions are students whose initial writing is bad and who do not respond to the supervision for some reason. I have never experienced a student whose initial writing was above standard and who did not improve.
Mind that this is still field-specific. In particular, in the humanities, wording holds a much higher value and thus things may be different. (It is for that reason that plagiarism is much more prevalent in those fields.)
There is a generally agreement and understanding across academia that theses must contain the student's own work. However, when it comes to details, the customs vary dramatically.
In some places BSc students are expected to come up with their own project proposals and are free to execute them as they will under a gentle advisory guidance of their supervisor. In some places, projects are specified and proposed by academics, together with the list of recommended literature and expected outcomes; students simply go through what is effectively a taught material delivered in one-to-one mode.
Considering the dramatic variation of what the projects are in form and purpose, it is not surprising that there is also difference in details, e.g. the role of supervisor. It often stems from the fact that some supervisors perceive the projects as some kind of competition between staff. This is often reflected when it comes to marking, and some staff make a major effort to secure higher mark for the students they supervised, while offering a much lower mark to students of other supervisors. The situation can become particularly nasty if "successful supervision" is a promotion/progression criteria in a Department.
Needless to say, if some academics wrongly understand the quality and mark of theses as criteria of their own success, rather then the success of their students, their behaviour can deviate far from being fair and objective. It is quite common that such academics may become overly pro-active and offer to proof-read theses, edit them, etc. In one extreme case I've seen an academic who kept all good projects from past years in his office and could offer a struggling student to "look at" a successful project on a very similar topic, effectively encouraging plagiarism.
This behaviour if unfair to other students and detrimental to students' learning. Unfortunately, academic administrators often turn a blind eye or even support this sort of behaviour, because it keeps the struggling students happy and allows them to pass, improving the statistics of outcomes for the department. This is particularly typical in countries with strong marketalisation of Higher Education, where education is considered a service, and students are treated as customers. In this model, administrators find nothing wrong with keeping the clients happy, and may even reward academics for "supporting students who need support", creating an additional incentive for the wrong behaviour.