I've been asked many times: "Eva, what makes somebody a successful PhD student? Why do some students who had great grades in their undergraduate program and in their masters, suddenly start to have trouble when they start their PhD program?".
Success in a PhD program is not only related to being a good student. Yes, being a good student is THE prerequisite for starting a PhD program, but it's not the only necessary condition.
Without good grades and a good grip on the material of your field, you don't have the understanding to dig deep into your field and explore the boundaries of the current knowledge in your field.
However, there are a number of essential research skills to develop as a PhD student. Being aware of these skills is one thing - and actively working on improving their skills will facilitate your path as a PhD student (not that with these skills success will come for free - hard work and many iterations are still the stuff that make up science).
Here is a list of skills you will need during a PhD program:
1. Study on your own
You'll need to be able to identify, honestly, your lacks in knowledge, and study on your own to gain a better understanding of your topic. You'll need to master the skill of studying for understanding - not just studying in order to pass a test. Be prepared to hole up in your room or the library with a text book of a course you never took, and chew your way right through it. This way of studying might or might not fit your learning style - and you might find it difficult to stay focused for long stretches of time.
2. Reading for quickly grasping results
Besides the skill of studying a new topic on yourself, and deeply delving into a topic, you also need to develop the skill to quickly scan a large number of papers, and filter out the results you need. Some papers (say: the seminal papers on which you will build further) are papers that you need to read in depth, go over all the derivations and understand every single fiber and though of it. But some papers will just serve you to bring some data, or to give you an idea on how to improve your experimental setup. Learn when you can go and quickly rob the ideas you need, without chewing over the entire paper endlessly. Understand the different phases of reading you need.
3. Finding the gaps between papers
If your research question is not defined at the outset of your PhD research (and I wonder: when ever is it really defined by the PI before the grad student delves in and starts spinning further from the -sometimes loose- ideas of the PI), you will need to describe in better detail what exactly you will try to answer in your PhD research. A good way to better describe your research question, and to start your hunt, is to read for having a good overview of the current state of understanding of the problem you study, and then compare the different papers to see where the gaps in the current state-of-the-art are. Do you find conflicting data? Different opinions? These situations are typically red flags for you to stop and look better at the difference between the papers you are studying.
4. Testing the boundary conditions of theories
Advances in science are made by those who try and push the boundaries of our knowledge. Whenever I get stuck on theoretical work, I meticulously go over the assumptions of the theories that I have been using, and test the boundary conditions and domain of validity of the used theories. Many times, when you get stuck on theoretical work, it is not your derivation that goes awry (you can derive and derive it 20 times and still come up with the same formula that then in a simulation will give you 3+4i as a result) - you simply are running out of the bounds of the field of application of some theories.
5. Academic writing
Many tweets (check out #acwri) and posts have been devoted to academic writing. As simple as it is: you can't get your PhD degree if you don't write a 100k book dissertation or get a number of papers accepted for publication (depending on the system your university has decided upon). You might have written a couple of lab reports, and probably even a Master's thesis before - but lo and behold, serious Academic Writing that takes you to the PhD level ain't nothing like that. I haven't come across a single person to whom writing their first article or the first chapter of their dissertation came naturally and effortlessly. It's a pain in the beginning, but it's just like learning to ride a bike. Practice makes perfect (or at least: practice makes you faster).
As an undergraduate or Master's student, you can be in a reactive mode, where you simply take on the tasks that are thrown at you, and make sure you deliver them by the homework deadline or study by the exam date. For a PhD program, especially research-based programs, where you can Do Whatever for 4 years, as long as your book is written at the end of the ride, you will need to learn how to plan your work. Learn to subdivide your tasks, from the long-term planning, down to your daily to-do list. You can find some inspiration on productive planning and the use of lists in this linked post.
7. Managing your time
If you want some inspiration on how to structure your time, check out the academic schedules series that is running here at PhD Talk. It will take some iterations (just like research), but ultimately, you will find a time management system that works for you (or you might like to keep evolving your system as you learn more about time management, and because you might end up liking to experiment with different approaches). You need to learn to understand that now you are in charge of your program. You are not sitting here and making homework - you are the owner of your research project, and it's all up to you to bring it to success.
8. Designing experiments
In undergraduate and MSc level courses, you will follow experiments that are well-understood and that are perhaps described by international codes and standards. Once you start pushing the boundaries of the understanding on a certain topic, you might need to device an entirely new testing method to isolate the parameter you want to study. Experiment design is not a course you can typically take, and it will take patience, failed setups, and a lot of coffees with the senior PhD students or lab staff to come up with a setup that works.
9. Taking ownership of your work
As I've mentioned before, PhD level research is not about sitting and waiting for your adviser to give you instructions on which steps to follow and just sit and crunch numbers for him/her. At the end of your PhD, you need to show the (research) world that you are an independent researcher, ready to develop your own lines of research. Your PhD is your first step in this direction. Typically, your adviser will guide you more in the beginning, but gradually will let you loose and just ask you for your main findings. Understand that your PhD is your metamorphosis from guided MSc student to independent researcher - and anticipate the responsibilities associated therewith.
10. Bouncing back after a setback
Every PhD student goes through the Valley of Despair a number of times. Life doesn't end when you reach a dead end in your research. It's OK to be mad at the world, your experiments and your supervisor for a weekend, and spend said weekend reading fiction / gaming / cooking / hating research. But that phase will and should go - and then you need to scramble yourself together, and make course corrections in your research. With this big change, comes the humility of accepting that you are wrong, with accepting that you can't know from the very beginning what is the exact path of research. It can be painful and frustrating, but you'll need to develop the skill of taking a deep breathe, letting go, and starting over new.