This blog post is penned on my second weekend arriving in the US. After an intense week of settling into a new country and meeting many “familiar names” in person, some of my prior convictions have been reaffirmed while some fresh insights pop up. Also, with another application season approaching, friends from my home country are seeking my counsel. So, I believe now is an opportune moment to reflect upon my own experience and share some lessons learned in the process, particularly from an international student’s perspective.

(Disclaimer: I think a huge difference exists between the experiences of domestic and international students when navigating PhD admissions in the US. I hope this post can give more information to the latter, but apparently, my viewpoints are prone to be biased and may best resonate with students who attend college in China.)

Deciding Which Program to Apply To

PhD or MS? Or straight into work?

During my application process, a popular joke among my friends was “Turns out, deciding to apply for a PhD is the hardest part”. Though ironic, that’s true… I’m still uncertain if I made a right choice, but I can share a bit about how I arrived at my decision.

Experience it. Opting for a PhD means you’ll do research for the next 5+ years, possibly even for a lifetime. This is what sets it apart from the other two options. (Note: unlike in China and some other countries where master programs might be more research-oriented, master programs in the US are primarily tailored to equip you for the workforce - you may focus on research, but that’s not the main stream and you’d better not say so in your state of purpose (SoP) for a master program :) Therefore, it’s highly recommended to get a feel for research during your undergraduate years. Whether it’s assisting in a campus lab, undertaking a research internship in the industry, or collaborating with international faculty – all these experiences are valuable. However, for some people, it may still be hard to tell whether doing research is the best for them. In such cases, gaining work experience may help you compare. Personally, I began assisting in a school lab during my sophomore year and later took up an engineering internship the following summer. Although I fully enjoyed that internship, it made me realize that I need more practice on high-level project design and directly going to work may restrict myself into very niche tasks. This realization steered me towards prioritizing research during the remainder of my college years.

An interesting observation: Comparing CVs of students who attend college in the US and China, it’s evident that American students tend to have a more varied college experience. Some of my Chinese peers expressed concerns that non-research-oriented activities might be a waste of time if they eventually decide on a PhD. But as the earlier joke suggests, experiences are about “experiencing”, which might make that most difficult decision-making part easier. If you’re certain about research from the outset, that’s commendable and just be committed to it; otherwise, investing some time to try different things is worthwhile.

Feel free to have backup plans. Once you’ve decided to pursue a PhD, congratulations! You’ve chosen a challenging path. PhD application is competitive, especially for CS/AI. But a kind reminder here is to always allow yourself the flexibility of backup plans. During my application process, I was afraid that having backup plans might make others perceive me as less committed to the PhD pursuit. But this isn’t true. It’s completely acceptable to simultaneously apply for master’s programs (as I did) or explore job opportunities (as several of my peers did). If you think having backup plans can help release your tension, just do so.

Talk to senior people. The biggest lesson I learned from my application journey is to never shy away from seeking advice, particularly from senior people. I’m now starting my PhD journey at Stanford - a program that initially wasn’t on my target program list (will discuss about it later). Stanford CS offers both master’s and PhD program but applicants can only apply for a single program at Stanford each year. Given that Stanford was my dream school (my interest in AI/NLP was largely spurred by the exceptional online courses Stanford generously made available to the public), I initially considered applying for a master’s, thinking it might increase my chances. My rationale was, “Perhaps I could apply for the PhD program once I’m already pursuing my master’s there.” When requesting recommendation letters, I talked with my referees about my program list and one of them ardently advised that I aim directly for Stanford’s PhD program. She expressed confidence in my capabilities and emphasized that transitioning from a master’s to a PhD, even within the same institution, can be quite competitive. Additionally, there’s often a heightened expectation regarding your accomplishments and track record. Had I not asked her for advice, I might never have applied for—and subsequently been accepted into—Stanford’s PhD program. The essence of this tale? Break out of your shell and converse with those more experienced; the insights gained are invaluable.

Picking the school.

Crafting a well-thought-out list of target programs is vital. Below are some factors I considered when curating my list. (I only focus on selecting PhD programs here, for selecting master’s programs, Zhenbang You has an amazing guideline in Chinese)

• PhD is a long commitment so I only select schools that I truly want to go. Applying indiscriminately just for an offer hurts both you and your advisor.
• PhD is mainly about research, so I only consider schools which have professors that I’m interested in working with.
• PhD is long and encompasses experiences beyond research, so I place considerable importance on non-academic aspects like location, climate, and safety.
• PhD admission can be random. There’s a chance your ideal professor isn’t accepting students in a particular year. I tried emailing professors to ascertain their availability and didn’t mention them in my SoP if they confirmed they won’t. Personally, I think emailing with this concrete question should be fine according to Yonatan Bisk’s amazing blog on “Should you email professors?”.
• One thing I wish I had done was engage more with my peers, especially those who have their undergraduate studies in the US. You can know your position and gather many useful information from such interactions.

Creating Your Application Package

“references, references, references”, but how? There’s a prevailing consensus that connection plays a pivotal role in PhD admissions. That’s why recommendation letters stand out in your application package (Note: an application package typically consists of your transcript, CV, SoP, TOFEL scores for international students, and 3 recommendation letters*). According to Karpathy’s blog back in 2016, the mantra of PhD admissions is “Getting into a PhD program: references, references, references”. However, a major problem for international students is that it’s very hard to get references from renowned US faculties.

A common way to build such a connection is through summer research internships at US institutes. Given professors’ limited bandwidth, you’d better secure your position early - you may send out emails after the Christmas break. Generally, assistant professors are more likely to host interns and I think their references are also powerful since they are very active in academia.

That said, if you’re unable to obtain a reference from US faculty, it’s not the end of the world. After gaining admission to several programs, I had conversations with several senior faculties and many of them told me besides the referee’s name, they actively looked for details in the letter. Thus, value every collaboration, and feel free to remind your referees to add more details in the letter if they are not very familiar with writing them.

*: As of Fall 2023, many PhD programs no longer mandate the GRE. It’s essential to review each program’s prerequisites in advance.

About paper. As the field of CS/AI/NLP is getting increasingly popular these years, it seems like you need at least one paper to get into top PhD programs. This may be true (not sure), but one thing is verified by many faculties - a bunch of papers won’t strengthen your application that much, and emphasizing a bunch of N-th authored papers may even hurt your application.

Leave enough time for your SoP. While some people think that SoP is not that important for engineering students, I hold an opposite view. Of all components in your application package, the SoP is what you have the most control over. So, what should you include in your SoP? According to Philip Guo’s blog post, your SoP should be research-dense. That means “the majority of your statement of purpose should be about research”. Besides, I want to add one more point here - it’s crucial to allocate more space to your future research plans rather than merely recounting past experiences. Your experience can be found in your CV but your insights and tastes on research can only be found here. If your ideas resonate with your dream professor’s, your chance of getting an interview or even acceptance will greatly increase.

For concrete examples, I highly recommend cs-sop which includes excellent SoPs from many amazing guys.

About other stuffs. You definitely need to study hard in your undergraduate years, but honestly speaking, GPA and GRE/TOFEL scores don’t have a high weight in PhD admissions. It’s wise to allocate more time to research or other more important things.

Preparing for the Interviews

After assembling your application package and completing your online applications in December, you might be tempted to take a break. But hold on – the journey isn’t over! Most top CS programs include interviews as part of their admission process, given the abundance of strong applicants, it’s crucial to be prepared for them.

A definitely asked question: Describe one of your research projects. I didn’t meet an exception in the 9 interviews I took. Therefore, it’s wise to be well-prepared. Anticipating the time you’ll be given for your response can be tricky, so I advise crafting a 3-sentence summary, a 5-minute detailed response, and a comprehensive 15-minute description of your project. You also need to be familiar with all the details around your chosen project since professors are likely to ask you some follow-up questions. Tailor your response to the specific professor you’re conversing with. For instance, if they’re well-versed in your field, you might skip the background information. If a segment of your work aligns with their interests, delve deeper into that area.

For international applicants, honing your spoken English is beneficial. You definitely want to get your brilliant ideas across.

Stay updated with current trends. The wait for interview invitations can be nerve-wracking. Nevertheless, during this period, it’s vital to stay abreast of recent developments in your research area, particularly new arXiv publications or Twitter threads from your desired research groups.

Document and reflect on questions. When the interview period kicks off, a good practice is to introspect on each interview you took - write down the questions you just got and think about how to answer them better (if your English is not that fluent, you can also write down the refined answers - I did so). This practice is helpful for me as I found several questions appeared again in subsequent interviews.

Be grateful! Professors are busy. Therefore, being granted an interview signals their keen interest in you. I felt truly grateful for getting those interviews as it’s my first time to be able to directly talk with those “big names” in my mind. Typically, at the close of an interview, you’ll have the chance to pose your own questions. I used this chance to ask research-related questions that I have been puzzled about and I really learned a lot from their answers. This is actually the most meaningful part in my lengthy application process.

Closing Thoughts

My journey has just begun but it’s just so amazing to see my previous efforts took me here. Applying for a PhD is challenging but rewarding. Hope some parts in this blog post help and good luck!