Hang in there

A wise person once told me that doing a PhD is as much a test of endurance as it is a test of intelligence. You face years of late nights, mountains of literature, numerous false-starts and dead-ends, and the nagging fear in the back of your mind that it might not be all that worth it.

Whether or not it is worth it is a question that only you can answer. Financially, it probably isn't. People who do PhDs tend to earn less over their lives than those who do not. They take longer to settle down and tend to delay parenthood and home-ownership until later in life. On the other hand, a PhD is your ticket into academia: the chances of getting a good, stable academic position without a PhD are, now, practically nil. A PhD can also gain you respect from the community: although I seldom use my title, it is useful when I do. Finally, there is the satisfaction of knowing that you achieved something most people never will, or never could. Personally, I did a PhD because I wanted to see if I could. It was the challenge of doing it that appealed to me. With my undergrad degree (first class honours in Information Science) I could have gone into the corporate world and made a very good living. I'd probably be in a high management position now, making a lot more money than I am making as a researcher, but I'd probably be miserable at the same time, because I'd never know how far I could have gone in research. And at the end of my life, I'd be asking myself, how much of a difference did I really make?

There are several factors that contribute to a successful PhD. Firstly, you must have a good supervisor. In fact, I'd go as far to say that you need two supervisors, one senior and one junior. By that I mean that you need one supervisor who is an established academic who is well-respected in their field, and another supervisor who has recently completed their PhD. This is because the junior supervisor still remembers what it is like to do a PhD in the current time, while someone who did their PhD twenty years ago has probably forgotten. You must actively engage with your supervisors, to make sure that they are up-to-date with what you are doing and what you plan to do. A supervisor who is ignorant of what you are doing is a useless supervisor. Don't keep them in the dark!

You must have a clear idea of what your PhD is about. In other words, you must have a hypothesis, and research questions, and research goals. I even went so far as to make these explicit in the introduction to my thesis. It might take you a while to be clear about these, but you'll save a lot more time in the long run.

You must not underestimate the requirements for a PhD. Most universities award a PhD for "a significant original contribution to knowledge" (although most of them do not define "significant" "original" or "contribution"). So, a new algorithm for determining the contributions of the input variables of a neural network probably wouldn't be enough for a PhD, while the algorithm in the context of a rigorous theoretical analysis of the neural network itself, along with an analysis of the algorithm, probably would.

You must not over-estimate the requirement for a PhD. In other words, you're not going to find a cancer cure, or discover the Higgs boson, or bring peace to the Middle East during the course of your PhD. Your PhD research problem needs to be enough for a PhD, and no more. Feature-creep kills PhDs as easily as it kills software projects. From chatting with more senior academics, I've come to believe that this is a more common problem than underestimating a PhD. A good supervisor will help you define the scope of your PhD project, while a bad supervisor will not. Get rid of a bad supervisor and find a better one. Or, at least seek help elsewhere.

You must stick with it. Everyone has a period during their PhD when it all looks hopeless, when you don't want to go on and just want to pack it all in. Hang in there. If you've decided that it's worth it before starting your PhD, it probably is still worth it, even if you don't feel like it. The enormous high you will get when you pass your examination is something  you'll not feel often in your life (I found out I had passed my PhD examination two weeks before becoming a father, so I had all of my enormous highs in a short period of time).

It is likely that your examiners will want you to make some revisions to your thesis. Don't take this personally! The best thing to do is to just shut the hell up, make the changes as quickly as you can, and get the degree confirmed. Don't waste too much time arguing with the examiners, unless they are egregiously wrong (one of my examiners was egregiously wrong, in several places, and making the changes he wanted would have made my thesis worse, not better. In the end, I had to show my examination convener a pile of literature that showed that the examiner was wrong, and educate him on how innumerate the examiner was).

When you have passed your PhD exam, the next step is to get a job. If you want to be an academic, that means getting a post-doc. If you're organised, or lucky, then you might even have a post-doc organised before you finish your PhD. Don't restrict your search to just the field you did your PhD in. My PhD was in computational intelligence, but my two post-docs were in ecological informatics, and my current position is in ecological modelling. I'm not an ecologist, by any stretch of the imagination (although I do know a lot about ecology now) but because I am a flexible and fairly clever person I was able to work in these fields, and work effectively. Know what skills you have, and know how to advertise them to potential post-doc supervisors.

Once you're in a post-doc position, the only goal you should have is to publish as many papers as you can, as widely as you can and as quickly as you can. It can also be good to co-supervise some PhD students of your own, to attend conferences, edit journal special issues, and generally show the world that you are a good, hard-working and professional researcher.

But, above all, you must hang in there!