I recently received my MSc result, and it was lower than I expected, in fact lower than most of my work throughout the year. I thought this was strange and contacted my supervisor, who said that the reason why was because I was 'thrown off' by the data which suggested a conclusion different to what would have been the case in a statistical analysis. However, during the supervision process I had asked if a statistical analysis should be done to test this idea, and he said no, my current approach was good enough. I also had justified why my approach did not need to be statistical in the dissertation itself.

Is this a grounds for appeal? Have I been mislead in the supervision, and is this a ground?

Your supervisor is not there to teach you only guide you. The research is all your own so you can choose to take his advice or not, the score is all your own responsibility.

I know that sounds harsh but I know from experience!!! My dissertation did not get the score I had hoped for - or had been indicated. I vividly remember my last couple of sessions with my supervisor where he could come up with no suggestions for improvement and we were both very happy with what was there... so to get a score about 10% lower than hoped was a real 'bag over the head punch in the face' moment.

Others might say differently but is it worth the hassle? If you have passed then congratulations - you have a Masters Degree which is a very good achievement, in time you will appreciate it.

One thing you'll encounter throughout your academic career, is that what one academic thinks will not be the same as another. This is really, a foreshadowing of what Peer Review is like on your academic work when you begin to submit to journals, book publishers etc. You'll get reviewers who love your work, and reviewers who hate your work (i.e. the dreaded Reviewer 2!). Sometimes you'll get up to four reviews that may contradict each other.

Your supervisor, no matter how much support and guidance they give you, cannot guarantee the mark you want, because they cannot generally predict how the examiner is going to view your work. So while they may have, in their honest academic expert opinion, felt it was ready to go, that doesn't mean the examiner(s) will think the same way. There is no purely 'objective' measure of a thesis, it will always be, on some level, a subjective reading. It's the same as submitting a journal article for publication. You and your potential co-authors might feel its ready to go, send it off, and it comes back as an R&R or a reject.