Inside Ph.D. admissions: What readers look for in a Statement of Purpose
Actually, I can’t speak for admissions committees in general — only for myself as a faculty member responsible for weighing in on graduate admissions decisions in particular STEM fields. (I am at the intersection of two STEM fields — computer science and linguistics — and review applications in both doctoral programs at Georgetown University. This advice pertains to Ph.D. programs in the United States, which typically include a master’s degree and can be expected to take 5+ years in total. Ph.D. programs in some other parts of the world are structured differently.)
The statement of purpose (SOP) is considered alongside grades, test scores, CV, letters of recommendation, and sometimes a writing sample. All of these are important for those reading your application (generally faculty) to get a holistic impression of you as a candidate. By the time you are applying to graduate schools, the SOP may be the part of the application you have the most control over.
The SOP is an exercise in persuasive writing (an important skill in academia!). When considering an application, I ask myself about three criteria:
Qualifications: Does the candidate have the preparation to begin Ph.D.-level courses and research in my department/research group?
Focus: Does the candidate demonstrate a mature awareness of the (sub)field and how they will contribute to it?
Fit: Do the candidate’s research interests — subfield, topics, methodologies — mesh with the kinds of research performed in the department? Or (if considering the candidate for my research group), the kinds of research I’m excited about and feel comfortable advising? Will the candidate bring diversity, new ideas, and fresh energy to the program/group?
As an applicant, the Qualifications criterion is the most straightforward: it is about your record. Focus is about what you anticipate doing in your Ph.D.: beyond stating a subfield, you should put some thought into articulating what you are most interested in and how you would approach research as a Ph.D. student. Fit is hardest to address directly in the SOP — as a candidate, you are probably not intimately familiar with the specific department or program you’re applying to — but you should mention why you’re applying to that program.
I elaborate on these criteria below.
A Ph.D. program is training to become a scientist/scholar in a discipline. Though successful Ph.D. students share many of the same qualities as successful master’s students, it is important to recognize that they are distinct endeavors: a master’s program revolves around coursework, whereas for a Ph.D. student, the ultimate goal is success in research. So for master’s applicants, grades in relevant courses and test scores are an important, if not primary, basis for predicting future academic success — whereas in a Ph.D. application, excellent grades/scores are a necessary but not sufficient condition. Hence the importance of the SOP (and letters of recommendation).
The main way to demonstrate preparation for the Ph.D. is to summarize your research experiences thus far. Have you been mentored in research in a university setting? Explain briefly: What problem were you trying to solve and how? How did you contribute? What progress did you make? Was there an outcome such as a presentation, publication, honors thesis, or award? Did it help you to discover new problems you’d like to examine in the future? This narrative will be most credible if it is backed up by an enthusiastic recommendation letter from your mentor. Achievements should be listed on your CV as well.
You may want to mention other learning experiences that helped prepare you for the discipline: for example, if you are applying to study second language acquisition, experience as a language instructor will be relevant.
Based on the experiences that underlie your qualifications, your SOP should demonstrate a certain level of familiarity with the discipline. This does not mean you need to give a laundry list of things you’ve learned, but you should articulate how your contributions and ideas relate to important questions in the field, using the language of the discipline.
Moreover, you should have some insight into how you want to approach a Ph.D. in the field. This does not mean you need to propose a dissertation topic! But you should have an initial sense of the subfields, topics, or approaches that you find most exciting and want to specialize in. Think about the ways people in the field self-identify. For example, you might situate yourself as more theoretical or more applied, more quantitative or more qualitative. You can argue that your experience with some specific topic gives you a foothold to continue working on that topic—or you can indicate your intention to broaden or shift your focus.
Fit is about whether the particular program is right for you, and you are right for the program. This can come down to all sorts of factors beyond what’s in your application — factors such as whether the research strengths of the department match your specialty area, and which faculty members are looking for new advisees that year or are about to retire. The admissions committee will be looking for your “path to victory” as a student. However brilliant you might be, you’ll need mentorship and training suited to your development as a researcher, and the committee won’t (shouldn’t!) admit students that it thinks will have a hard time succeeding.
So to demonstrate fit for the program, it’s a good idea to name 2 or 3 faculty members as potential advisors, and explain which aspects of their research appeal to you. In addition to underscoring your fit for the program, it will also be used in the admissions process to help route your application to those faculty members for their input. As a general rule of thumb, I recommend 2 or 3, because if you only name 1 person, there’s a risk that they will not be taking new advisees, which will hurt your chances; and if you name a large number of faculty, it could make your interests look unfocused. Do your homework and browse websites of interesting faculty in each program you apply to. Also keep in mind that different faculty have different roles: in many departments, it is the tenure-track/tenured faculty who do the bulk of the research and advising of Ph.D. students.
Writing an SOP is hard. When I was an applicant, I found it awkward and intimidating. It may help to consider that you are not being asked to write poetry; you are being asked to make an argument. The point you are arguing is that you would make an outstanding Ph.D. student in a particular field and program. This is the implicit goal of every SOP, so you do not need to say explicitly “I believe that I would make a great student”. Instead, focus on providing solid evidence and details regarding your potential with respect to the criteria of Qualifications, Focus, and Fit. You can make the case with arguments like “(Research project) gave me experience with (topic or skill)”, “I am interested in (research area) — in particular, (topics)”, and “(Department/potential advisors) would be a good fit because…”.
How long should my SOP be?
1 or 2 pages should suffice. Don’t pad it with flowery oratory; focus on the persuasive argument. Your life history before you entered the discipline is probably not of much interest to the committee — unless it’s something really unusual!
How should I go about writing the SOP?
My advice is to start well in advance of the deadline, write a bad draft, get feedback from a mentor such as a faculty member or current Ph.D. student, and revise. Be sure to give the SOP to your recommendation letter–writers so they can echo the main themes.
Should I discuss nonacademic activities/achievements?
Evidence that you would contribute to the field and department you are applying to more broadly, beyond getting good grades and doing good research, is welcome. If you have served as a TA, have participated in outreach on behalf of your field, or have demonstrated strong leadership and communication skills, those are worthwhile qualities for you (and your letter-writers) to mention. But they should not be the centerpiece of your argument.
Should I comment on weaknesses in my application (such as some bad grades)?
Maybe. It could put the reader’s concerns at ease if you have a good explanation. However, this can be a double-edged sword, as it can draw further attention to weaknesses rather than strengths, or even come across as making excuses. Ask your letter-writers for advice; one of them may offer to put the explanation in their letter, where it will sound more authoritative.
Where can I find examples?
Update: For further discussion, check out the NLP Highlights podcast episode on preparing Ph.D. application materials.
Thanks to Amir Zeldes and Chris Brew for helpful feedback on a draft of this post.