What is a good answer to the question 'why do you want to do a PhD?'. I've never got as far as the interview stage before and I'm worried about messing it up, any tips?:$

Before we suggest a 'good answer'....

...why *do* you want to do a PhD?

because i've always wanted to do one, because i'd like to prove i can do independent research and have good ideas of my own and put them into practice. i thought that might come across as a bit lame in an interview though!

Because you want to acquire the skills necessary to become a dedicated researcher?

If you want to do a PhD just for the hell of it then I suggest you really think about why you want to do it. I was in the same boat as you 6 months ago when I was about to have my interview.

Tell them that you like doing research, you like working independently, have wanted to do it for a very long time. Finding out new things interests you and how you have immersed in your field (whatever is it) when you did your undergrad and Masters.

Be prepared, they will ask you more questions about your research projects, and how you cope with pressure, how often did you meet with your supervisors when you did your masters, if you know what a PhD entails, and what a PhD is etc...

Hope this helps