Yes, that is correct. It should be written thus: "master's degree". It has an apostrophe s at the end (rather than an s followed by the apostrophe). If you were to refer to the specific title of the master's degree, such as a Master of Arts or a Master of Fine Arts in xyz, then you would capitalize the degree. As for how to rate my work, I will let EditorWorld know that you are having difficulty, and they should send you an email explaining the correct procedure. I do very much appreciate your 5 rating! Let me know if you have any further questions.