PhDSciNet Interview 9: After the PhD — The Hair-Pulling World of Postdoctoral Research

Historical interview: The following preserves the research experiences and personal views expressed in the original manuscript.

PhDSciNet Interview Series

After the PhD: The Hair-Pulling World of Postdoctoral Research

For doctoral students in science and engineering, a postdoc has essentially become a necessary step toward a faculty position. A postdoc is like the entrance to a maze leading to a university job: you may reach your destination quickly, take a winding route, or end up at a dead end. But who can predict that accurately?

How do you find a postdoc? Should you join only a highly prestigious group? What does an ideal supervisor look like? How do you make the most of a postdoctoral appointment? How do you adjust when changing research fields? Today's interview addresses all of these questions. Get ready for some practical insights!

Introducing Our Guests

Eureka: Postdoctoral researcher.

Calorie (卡路里): Postdoctoral researcher.

01 What Is a Postdoc?

Question 01: Why did you choose to do a postdoc?

Eureka: My reason for finding a postdoc was actually very simple: at first, I was just too lazy to look for a job. I did not know what I wanted to do, and I felt I was still fairly young. My first postdoc offer happened to arrive quite early, and everything looked reasonably good, so I accepted it. As I carried on, I gradually felt like a horse entering a narrow passage with no way to turn back. I could only keep doing postdocs, and eventually the goal became finding a faculty position.

Calorie (卡路里): For me, it was a buffer period. When people ask what I am doing, I sometimes joke that I am a temporary worker. Although it is a joke, it is also true. At the time, my qualifications were not sufficient to apply directly for faculty positions. I had no clear direction in industry either, and I was rather confused about what I wanted to do. So I decided to do a postdoc first and give myself some breathing room. It also gave my academic aspirations another chance. I changed research direction and continued as a postdoc to explore my interests and abilities from more angles, and to understand myself more deeply during that period.

[Sometimes a choice is made blindly, out of inertia or laziness, and the reason for that original choice may only become clear further down the road.]

Question 02: What is the purpose of doing a postdoc?

Eureka: Postdocs come in all kinds of forms. Because of outside perceptions, people may assume that a postdoc is above a PhD: a more demanding, more advanced job involving higher-level, more specialized research every day. But I do not think it is necessarily like that. There are many different kinds of postdocs. Some people can drift along rather leisurely in a group. Others join a group to give themselves a buffer period while looking for a job. Of course, for most people, the main purpose may be to publish high-quality papers and obtain a good stepping stone or platform for a future faculty job search.

Calorie (卡路里): What a postdoc actually represents is a very practical question for most people. We are all in science and engineering. If you want a faculty position, most of the people in that job market have done postdocs. Unless you were exceptionally outstanding during your doctorate, you cannot compete with them in the faculty market. So people do a postdoc mainly to publish more papers, meet a new supervisor and new colleagues, increase their chances of finding a faculty position, build up their academic experience, and prepare more fully for the faculty job market.

There is also a practical consideration. Under the circumstances at the time, if you wanted to return to mainland China to find a faculty position, many universities had requirements concerning the length of postdoctoral experience. Some job descriptions, for example, explicitly required 36 months of overseas postdoctoral experience. That was a concrete requirement you had to consider.

[Postdoc: A temporary worker before a faculty position. Papers, papers, papers!]

Question 03: How do supervisors view postdocs?

Eureka: I think a supervisor may view a postdoc much as we view an undergraduate working on a final-year project or a graduate student: you are here to help me get the work done. The supervisor may think, 'I pay you a salary, somewhat more than a doctoral student, and you do not have to take classes like a doctoral student does.' They naturally hope you will arrive ready to contribute immediately and produce as many high-quality papers as quickly as possible. I think that is the mindset. Few supervisors will have the same patience to train a postdoc as they do to train a student. Unless they really click with the postdoc, or are genuinely very nice, they may not be willing to guide you onto an academic career path.

Most of the time, I think they assume that since you are a postdoc, your thinking must be similar to theirs: we are all here to publish papers together, so let us get the papers done quickly. Then, when you look for faculty positions a few years later, of course I will help write your recommendation letters. Overall, I think a postdoc is essentially something like a contract worker from a supervisor's perspective.

Calorie (卡路里): Yes. A supervisor certainly hopes that a postdoc can get started and produce results immediately, rather than expecting to train them as they would a doctoral student. People sometimes joke that doctoral students are the supervisor's own sons and daughters, while postdocs are the adopted ones. The relationship sits somewhere between an employment relationship and a teacher–student relationship.

[Three things to do promptly when joining a group as a postdoc: Move beyond your student identity, take on the role of a working professional, and get started producing results.]

02 How to Find a Postdoc

Question 04: When is the best time to look for a postdoc?

Eureka: In general, I suggest starting six months before graduation, or once your dissertation defense has been scheduled. You can begin looking at postdoc positions then, while preparing your résumé, personal website, and similar materials.

At the beginning, collect information widely. That might mean visiting individual group websites or university recruitment websites. Even more importantly, ask your supervisor. Ask everyone you can about which groups are hiring or whether they have any inside information.

Once you have gathered most of that information, start writing your first application letter. I suggest collecting all the information before contacting a prospective supervisor; otherwise, you may waste the opportunity to make a good first impression. I recommend putting more effort into preparation. If you are six months away from completing your doctorate, for example, you could spend the first three months preparing and the next three months sending emails in a concentrated way.

One thing to note is that postdoc recruitment differs greatly from doctoral admissions. In most parts of the world, PhD recruitment peaks in autumn and winter, whereas postdoc recruitment generally continues throughout the year.

Calorie (卡路里): If possible, you can also contact postdocs or doctoral students in the group first to learn about it. If a supervisor has certain personality-related issues, for example, we should try to gather information that helps us avoid possible future difficulties. After all, a postdoc may take two or three years. If the supervisor is difficult to get along with, try to avoid joining that group.

[Tip: Prepare six months ahead and gather information from several sources.]

Question 05: How do you obtain useful information?

Eureka: I think the best and most efficient way to collect information is simply to ask people. You may not get much information from your colleagues, because they are doctoral students or postdocs like you. I mean asking your supervisor, for example, and other professors with whom you have a good relationship. Ask them more often and see what information they have.

I have now done several postdocs, and most of the recruitment information I received came through internal referrals. For example, someone we knew from our group moved to location A and forwarded us an internal recruitment email from there: 'Look, this group has a vacancy and needs someone. Apply quickly.' I think this kind of information is actually the most effective.

Another thing we can do ourselves is visit the recruitment websites of all the universities that interest us. But I suggest not putting too much trust in the so-called 'job openings' section, because many supervisors or departments are very reluctant to update it. Recruitment information on group websites is often several years old. The position may already have been filled, but they still do not take the advertisement down.

So my suggestion is to focus on groups that interest you. Once you have identified them, email them directly and ask whether they need someone. I think many supervisors may offer to find a position for you if you are good enough, even when their group does not have a clearly advertised opening.

[Tip: Make good use of the connections around you and actively create opportunities.]

Question 06: For a postdoc, which matters most: location, university ranking, the supervisor's publications, or research direction?

Eureka: It depends on whether you ultimately want to enter academia or industry. If you want academia, location does not really matter, because the purpose of doing a postdoc is very straightforward: to publish papers, not to enjoy life. But if someone really wants to enter industry—for example, biotechnology—it is better to come to Boston or go to the Bay Area. If they work in AI or computing, it goes without saying that they should be somewhere closer to the Bay Area.

If your goal is academia, the supervisor should certainly come first. Is the supervisor highly accomplished? Then consider how quickly they publish, because some supervisors are very prominent but publish extremely slowly.

For example, my supervisor has published more papers in flagship journals than in all other journals combined, but those flagship papers take too long to produce. On top of that, US visa issues are very difficult at the moment, so I feel I do not have much time left here. I cannot stay long enough to wait for a flagship paper. Earlier postdocs from his group who published in those journals all worked on their projects for a very long time.

I think this is something you need to consider before doing a postdoc. Before I came, I only noticed how impressive this supervisor's publications were. But I overlooked a very important point: the work took a very long time to turn into papers.

I think you can write a simple calculation: multiply the supervisor's publication frequency by the length of time you can stay, and see what your expected publication output might be. Then you can decide where to go. Of course, the supervisor's character is very important too. If they are not a decent person, it is better to escape that difficult situation sooner rather than later.

Calorie (卡路里): My situation was actually quite simple. I wanted to be with my boyfriend, so location came first. That effectively meant one university. Within that constraint, I considered supervisors in departments that interested me. Of course, the ranking of these factors differs from person to person. If you are on your own and want to make it easier to find a job later, the university's ranking and the supervisor's publications are both very important.

Eureka: Let me add that sometimes I think university ranking is less useful than the supervisor. Rankings are for people who do not really understand the field. If you want to keep industry as a backup option, for example, they can be quite useful for impressing HR: you say you are from an Ivy League university and explain how highly your university ranks, and they are won over. But when looking for a faculty position, university ranking matters less, while your supervisor's reputation matters a great deal.

Calorie (卡路里): I think that is not always the case. In the US, where people's connections are fairly close, everyone in a small field may know each other well. But in mainland China, people sometimes know nothing about your supervisor or your field. In that situation, saying you come from Harvard can make you seem very impressive.

[Brief takeaway: A supervisor's character, publication speed, and the university's reputation all matter.]

Question 07: How should we choose a less prominent supervisor leading an ordinary group?

Eureka: Before coming to Harvard, my previous postdoc supervisor was not well known, and neither was the university. Its location was very good, but its ranking was very low. It was already quite inconspicuous within Canada—a second- or third-tier university, perhaps in the world's top 1,000. Its advantage was that the supervisor was very patient with students and willing to spend time on them. Perhaps because the university was small, the pressure to obtain tenure was lower, and he was even willing to spend time helping postdocs.

But I think the main point is that the supervisor should be a good person. Even at a small university, a good supervisor can still do a great deal for you. That supervisor of mine put considerable effort into recommendation letters and into revising my résumé and presentation slides, which was a tremendous help. He was also young and had recently been a postdoc himself, so he understood what you needed. Many of the students he has trained have gone on to university positions. He graduated his first doctoral student the year before last, and that student went to Harvard as a postdoc. He then recommended me to Harvard. The next two new PhD graduates after me, who were a couple, both went to Stanford. He also supervised a master's student who went to Princeton for a PhD. His students have had very good outcomes. So I think you should consider whether the supervisor is willing to invest time in you.

Calorie (卡路里): I think this is a very practical, results-oriented question: how much help can the supervisor ultimately offer you? Someone who is very nice and can provide real recommendations and support does not necessarily have to be a leading figure in the field. Some people take another route and look for young assistant professors. These professors may be at a stage when they urgently need to pass their own evaluations, so their desire to publish is as strong as yours, or even stronger. In that situation, though, you should be prepared: first, you may be under considerable pressure; second, there may be risks. Of course, the eventual benefits may be substantial. Because the supervisor is at that stage, as a new student or one of their first students, you may gain a lot in terms of publications.

Another point is that some supervisors state on their websites what percentage of PhD graduates or postdocs from their groups have found faculty positions. If they provide that figure, you can use it as a reference. It directly indicates how much their reputation may help you and how much practical assistance they may offer when you look for a job.

[Tip: A leading academic can be a good supervisor, but an ordinary supervisor can be good too. Look at the subsequent paths of students and postdocs to learn about the supervisor.]

03 Is a Postdoc Really Useful?

Question 08: Some people have done two or three postdocs and are still continuing. Is a postdoc really that useful?

Eureka: I am exactly the person you mean who has reached a third postdoc, but I still do not have a particularly good explanation. I do not think you need to dwell too much on this. You do not really need to worry about how many years or how many appointments you have done, unless you have a personal age requirement—for example, returning to mainland China before age XX—or an age limit attached to a particular talent program or professional title.

I think a postdoc should normally focus on research. When you have genuinely produced research that satisfies you, that is when you can say you have done enough postdoctoral work and can stop. But if, along the way, you decide you no longer want to continue and want to find a job in industry, that is fine too.

Calorie (卡路里): Most people in science and engineering who want faculty positions do postdocs. If you return to mainland China to find a faculty job, there may be requirements for the length of your postdoctoral experience, such as three years. There is also very serious age discrimination in mainland China. Some programs described as 'young talent' may have age limits of 32 or 35, or somewhere between 38 and 40. That can create a sense of urgency: I must find a job before a certain point. So it can cause anxiety.

Here in the US, anxiety about age is not particularly strong. Our supervisor once sent us information saying that people who obtained faculty positions had spent an average of eight or nine years as postdocs. We also thought that was a very long time, but perhaps people here in the US really are not in such a hurry. It also depends on the field.

I have noticed that the biology postdocs in our group are not particularly rushed. They think things through slowly and do experiments at a steady pace. By contrast, Chinese postdocs tend to feel greater urgency: they want to publish more papers and move on quickly. Because of the various requirements in mainland China, they hope to find faculty positions as soon as possible.

Question 09: Do postdocs feel anxious about being 'older' or having a 'low income'?

Eureka: I think age is a pressure people place on themselves. Chinese people may feel somewhat more anxiety about age than people from other countries—or perhaps a great deal more. Women, for example, may feel pressure about marriage. Being younger may make things easier, while finding a partner at an older age can be more difficult, and delaying childbirth means becoming an older mother; those are inherent disadvantages. But if you analyze age anxiety together with being a postdoc, I actually think they are unrelated. You would have these age-related anxieties in other industries too. They are not career anxieties unique to choosing the postdoc path. It mainly depends on your career plan. If you simply want an academic career, you do not need to worry too much about age, because faculty hiring generally considers your research output and publications.

As for income—sorry, but if you choose an academic career, your earnings at the beginning will certainly be far below those of classmates who enter industry. But you may have much more freedom than they do. It depends on what you want deep down.

[Brief takeaway: Every industry has its own anxieties and its own freedoms.]

Question 10: Do postdocs have work to do beyond research?

Eureka: Yes. At the university where I did my doctorate, I worked as a lab manager, mainly handling expenses for my supervisor. Whenever anyone in the lab needed to buy equipment or chemicals, they emailed me. I managed my supervisor's credit card and filled in online forms to make purchases for them. I also had to collect deliveries when they arrived. Then, every week, I found time to summarize the expenses in a spreadsheet and ask my supervisor to sign it. But I do not think administrative work is a major problem as long as it does not take up too much of your normal research time. In a way, it also develops some of your other abilities. For example, you learn in advance about managing accounts when you eventually become a PI yourself.

Calorie (卡路里): Yes. When I first arrived at the university, I also took on some group-management work. The circumstances were fairly unusual: I also had two students here, so it was quite natural for me, as a postdoc, to take responsibility for managing the lab. It was tiring at first, because I had changed research direction and had a lot to learn. Setting up the system also took a great deal of time. But I do not think it distracted me too much; it actually provided some variety.

Question 11: How does the mindset of a postdoc differ from that of a doctoral student?

Eureka: I think postdocs are certainly under more pressure than doctoral students. I mean people who have already decided to pursue academia. If you really want to become a PI and apply for academic positions, your postdoc will be very different from your doctorate. You cannot focus only on your research; you also have to think about what comes after doing your current research job well. For example, you may need to consider what research direction to choose as a future PI, start learning to write grant applications yourself, and begin changing roles. You need to learn to think from a manager's perspective and use your final period at a university to develop your abilities, so that you can perform better in future academic job searches.

Calorie (卡路里): Personally, I have not experienced a particularly large difference, perhaps because I changed fields. At the beginning, I was not very different from a student: both the subject matter and the experiments were completely different from what I had done before. When I first joined the group, I was a student both in mindset and in practice. But after a year or two, I think entering a different field and gaining a little understanding of it made me increasingly able to enjoy what I was doing. I found some projects genuinely interesting and wanted to complete them, turn them into papers, and present them as research outcomes of my own.

[Take an active role in developing yourself and prepare for your next step.]

04 How to Handle a Change of Research Direction During a Postdoc

Question 12: Is it feasible for your postdoctoral research direction to differ greatly from your doctoral research?

Calorie (卡路里): In practical terms, considering your stress and how smoothly you can make the transition, I suggest having some overlap between your postdoctoral and doctoral research. If you understand nothing in the new field, the research language, communication environment, work, and everyday experiments will all be completely different. I changed fields myself, and the pressure was quite high because nothing was familiar; everything was new. If there is some overlap, at least you will know on arrival where your strengths lie or what you can get started on immediately. That also makes communicating with your supervisor easier. Otherwise, you may be a complete beginner, as I was, often discussing basic knowledge with your supervisor. Another point is that a supervisor may not necessarily want someone from an entirely different field, so I was quite lucky. My supervisor was open-minded and felt that being willing to change fields showed confidence in yourself. But many other supervisors may want you to get started quickly and may not want someone from a completely different field in their lab. It varies from person to person.

Eureka: My current project is also very unrelated to my earlier research; even the research language is different. The first talk I attended after joining was given by another postdoc candidate. The entire title was one very long sentence, and I understood only two words in it. I even posted on social media that I could recognize only the two 'prepositions,' 'in' and 'and'; I did not know any of the remaining words. They were the kind of words that leave you confused when you walk in and just as confused when you walk out—all very long medical terms. At first, being somewhere like Harvard felt extremely stressful, because everyone seemed to be a genius. But after a while, I realized that in this kind of interdisciplinary setting, although you may know almost nothing about their discipline, they also know very little about yours. Gradually, I discovered that since they did not understand my field, I could try explaining it to them, and my confidence slowly returned.

In that situation, if both sides are interested in communicating further, many new and interesting projects may emerge. I personally really enjoy that feeling of interdisciplinarity. I have also consistently tried to extend my research into other directions, toward medicine and biology. I actively approach people in different fields and ask them questions. My own feeling is that I perform somewhat better in interdisciplinary work than I did in my original field. I have met many collaborators from different disciplines, and what we are doing now is very interesting. So I think you should not be afraid if your postdoc project is very different from your original background, and you should not be afraid to change direction. If you really enjoy academic work, I think you should boldly try new things, and you will gain many different kinds of inspiration.

Calorie (卡路里): If you have been immersed in different disciplines, you may also have a wider range of choices when looking for academic jobs. For example, if you have worked in both physics and biology, you can apply to either physics or biology departments when looking for faculty positions. You could also consider departments such as life and health sciences or biomedical engineering. Your range of options may be somewhat wider than other people's.

[Brief takeaway: Be cautious when changing fields during a postdoc. It may be a challenge, but it may also be an opportunity.]

Question 13: What do you plan to do after this postdoc?

Eureka: Look for a faculty position. I do not think anyone would deliberately throw a party to celebrate finishing a postdoc, because a postdoc does not mean the end. It is the beginning of the next, even more demanding stage of work, and you may have to send job applications all over the world.

Calorie (卡路里): Work. After the postdoc, it is time to get a job. I am in the thick of my job search now.

Question 14: What would you like to say to doctoral students preparing to look for postdocs?

Calorie (卡路里): I would say: think it through. I have seen very positive examples of postdocs, and examples that were not so successful. Whether you choose academia or industry, I think you should make a reasonable, objective assessment of yourself and plan ahead as early as possible.

Eureka: The more difficult things become, the harder you need to try.

Doing a postdoc is like finally completing the journey to obtain the scriptures after overcoming all 81 trials, only for the Jade Emperor to tell you, 'Come on, let us make a sequel.' And so you set off again on a journey full of unknowns. The strategy for this mission is to prepare thoroughly, take the initiative, judge objectively, seize opportunities, get your mindset right, and finish your postdoc sooner rather than later. We wish everyone good spirits!

PhD guests: Eureka and Calorie (卡路里)

Editor: Honey Peach Oolong (蜜桃乌龙)

Interviewer: Fantuan (饭团)

Audio recording: Calorie (卡路里)