Responsibility of supervisor to review draft thesis for plagiarism

Question

I submitted my master's thesis draft for my supervisor to review one month before submission. He told me to revise 2 chapters because I didn't cite/paraphrase the content. I paraphrased the chapters, sent them back to him for review. He said they're fine and I continued working on other parts of the thesis. Finally, I submitted it on the final date. Between that date and the submission date, we met many times to review the draft but he never mentioned those two chapters again, so I assumed that they're fine.

Then two months after submission, they told me that my paraphrasing was too similar to the original content, and they considered it plagiarism. They then decided I failed the thesis. I can still do a second attempt, since I am not yet expelled, but I was so disappointed that my supervisor didn't recognize it during the draft review. If he let me know about this sooner, I could still revise them, so that I don't have to spend another six months on a second attempt.

Is my disappointment justified?

Answer 1

First and foremost, it's your thesis and it's primary your duty to ensure that it's not plagiarised. To avoid plagiarism, don't paraphrase: write the thesis with your own words.

Then, depending on the university rules, the supervisor might also have the duty to check for plagiarism your thesis (e.g. through a plagiarism checker software), and in that case they could be considered co-responsible, in front of the university, for the plagiarism, but the main responsibility is still yours. You're really the one who knows whether your thesis is plagiarised or not.

So, no, your disappointment is not justified.