Why do you want a PhD?

The New York Times published an astonishing and depressing article yesterday about the lengths to which some Chinese students and their families will go to gain admission to elite academic institutions. Egalitarianism aside, their stance is painful to read about because it suggests such dependency on "prestige" and the belief that a famous degree will open more doors. (To be fair, I'm almost completely interpolating, but I'm not sure what other explanations are plausible.) A famous degree probably does open more doors immediately after college, but I'm confident the extra opportunity is not worth the price these families are paying. I went to one of these fancy-pants schools for undergrad; it was fantastic, and my peers were a constant source of inspiration, but I've no illusions that these famous schools are the surest or likeliest path to a wonderfully successful life*.

Moreover, I wonder when these students and their families will, if ever, switch strategies. How much prestige in life is enough? When can you turn away from opportunity? Would it be acceptable to go to one of these schools and then become a massage therapist? (I have a friend who did something like this. She told me she loved watching the looks on the faces of the parents of students at our private prep school alma mater when they heard she went to Elite Ivy U and now dances professionally at parties.) If the purpose of higher education at these institutions were more focused on serving society, I might have some sympathy for disappointment with less cerebral or influential careers; however, the majority of people seem to consider these educational opportunities largely as springboards for personal gain**. Massage therapy might arguably be more beneficial to others than many positions in finance.

This post is a round-about way of exploring motivations for getting a PhD. I assert that the following reasons are weak and insufficient:

• A PhD degree is prestigious. It is prestigious in some circles, but the prestige is shrinking or nonexistent among most of your probable reference groups. Regardless, if you need to feel that other people think you're smart, you're not so cut out for the intellectually humbling experience of research. Also, you will probably make a really annoying and arrogant collaborator.
• A PhD degree will help me land a tenure-track academic position. It's true that you can't become a professor in most countries without a PhD or its equivalent. However, the majority of people with PhDs in science who plan to become tenture-track professors do not actually become tenure-track professors, at least in the U.S. and Europe. This is not for lack of trying. The job market is terrible, and there's no reason to believe it will improve considering the trends in higher ed. This topic is probably worthy of multiple other posts.
• A PhD degree isn't a bad thing to get while I figure out what I want to do. Actually, there are several reasons why it might be worse than doing nothing. (1) In a philosophically and emotionally vulnerable phase of your life, you will effectively be drinking academic Kool-Aid. In many departments, academia is still the only socially acceptable career goal for graduate students, and many professors disingenuously promote the idea that anyone can get a professorship. These conditions will warp your thinking and preferences. (2) The financial and professional opportunity costs are large. Especially if you might want to work in industry, it might be better to start doing bench work right away, and you can discuss opportunities for advanced degrees with your coworkers. Many PhDs trying to go into industry find themselves overqualified or "incorrectly" qualified, i.e., industry would rather train someone cheaper who has more practical experience. (3) A PhD requires excessive time and focus, leaving you few opportunities to explore other directions.

It might be good to think about what percentage of your motivation can be attributed to the factors above. In my view, the only acceptable conditions for doing a PhD are:

• I want to learn how to do research, and
• I don't mind substantially reducing my immediate and probably lifelong earning potential.

The second point might not matter now, but consider that it might when you're older, trying to start a family, and have minimal savings. Unfortunately, there are huge gender differences here: a study of U.S. postdocs revealed that women are more apt to think about the material consequences of their professional choices on potential future families than men are, and this thinking might lead to the high attrition of female postdocs. (The implication is that low salary and career instability are an indirect source of gender discrimination in academia--I'll write more about finances during grad school in a future post.) In certain fields such as engineering, the PhD can precede huge increases in salary, but this is not guaranteed.

In summary, do your research before doing your research: Learn about the potential trajectories of your career and any large field-related trends before committing to a PhD. Do not procrastinate on thinking about what you want to be doing with your life in five and ten years. And remember that though the commitments can be annulled, it's better to leave sooner rather than later. If you've been exceedingly driven your whole life or have family members who have been encouraging you (explicitly or implicitly) to get a PhD, think especially hard about your motivations.

*Even if you define success as something lame like "get lots of money" or "become famous."

**That said, I think the more elite/wealthy the institution, the more apt they are to emphasize the importance of social service to their students and to make such career paths more accessible. I'm not sure if their students are more apt to take advantage of these opportunities, however.

Filter Feeding

One of the most fun and occasionally overwhelming aspects of research is learning about other discoveries in the field. Conferences can help, but to avoid local bias and increase coverage, it's best to rely on a steady diet of published papers. In the first year of grad school, you might not know exactly what your field is, and the papers might look like a sea of esoteric trivia. It's like that for a while. Gradually, as you hone in on particular questions and read more deeply, the mass will start to take shape, and you'll be able to understand better how one paper relates to another.*

The cliché is that reading articles is like drinking from a firehose, and it's clearly worse if you're totally new to the field and have to catch up. (I'm also assuming you know what your "field" even is. One can pick from many firehoses.) To develop a sense of which questions are popular and how they're being answered, I think it's handy to use a RSS aggregator to manage four kinds of feeds:

1. The contents of important journals: If there's a journal that everyone in your lab reads, whose articles you always find fascinating, or whose contents are potentially immediately important (arguably, Science or Nature), you might choose to subscribe to their complete tables of contents.
2. Articles that have important keywords: A journal's impact factor can have a notoriously poor correlation with the quality and utility of individual articles published in it. It's a bad and slightly dangerous habit to think that because something was published in a so-so journal, the research is only so-so. For maximum thoroughness, set up a feed at a citation database that notifies you of any article published with a specific keyword.
3. Articles that have cited important/cool articles: If you've found an article that you think is the coolest thing ever (or wrongest thing ever, and you're working on a response), create a citation alert to notify you every time the article gets cited. It's a good idea to do this for your own articles, too, and any articles that are central to your research.
4. Articles published by an important person in your life: Basically, your adviser, though you can cite-stalk anyone. Some advisers are prolific and do not communicate very much with their labs, and you might be interested in their work. 

I think the second feed is the most important. With this approach, I stumbled on an article that mentioned an amazing and unique data set. The authors were not well known outside their country, and I'd never before heard of the journal in which the article was published. I wrote the authors and offered to collaborate, and they kindly agreed to share all their data with me. This happened in a "hot" field, and it surprised me that no one else had asked before to collaborate with them. My take-away (with n = 1) is that you can get an edge if you read broadly.

For those new to RSS feeds**, the first step is to choose an aggregator that you like. I use Google Reader, which I can open from Gmail. I use it in conjunction with Helvetireader, which is easy on the eyes and pretty perfect for skimming titles and abstracts. Popular citation databases include Web of Knowledge, PubMed, Google Scholar and Scopus. (The first and last require an institutional subscription.) If you haven't yet, do some sample searches in each to find out which is best for your field. Even if you don't have access to proprietary journals or databases, you might be able to do something useful with open-access journals, PubMed, Google Scholar, and/or arXiv.

Currently, my feed gets roughly 200 articles/week. I'm not sure this is good, but one of my research subjects is very popular. For the vast majority of the articles, I don't read past the title; with a subset, I read the abstract very closely; and for the remaining few, I read the abstract and article itself (to some degree). Figuring out the right ratio of skimming to reading has been a big challenge for me. It would be interesting to see how scientists' reading habits vary.

*To a certain extent, these shapes are always changing--it's hard to know what methods or analogous systems might inform the questions we're pursuing.
**I'm not sure if it would be helpful for me to write a post that outlines this process in detail. Please let me know if you'd like one.

Writing the Statement of Purpose

A statement of purpose for a science PhD program is nothing like the essays one might write for college, medical school, or undergraduate scholarships. Those essays can read more like entries for a personality contest, where the implicit objective is to try to look like a sparklier snowflake than the other applicants. For a science PhD application, the statement should focus more on your ideas than you.

Female Science Professor (a.k.a. FSP) has written two fantastic essays (here and here) on what a statement of purpose should and should not look like. She has reviewed hundreds of statements and is a tenured professor, whereas I've seen only a few dozen and am a postdoc. Weight our advice appropriately.

The core of my advice is captured by FSP's statement that

I don't believe that the depth of your love for science, or any pursuit, correlates with how early you discovered that love, so I find such descriptions of childhood inspiration unconvincing in an application for graduate study in the sciences.

There is no need to make it sound like you've been fated to go into science, do research, or develop novel nonparametric methods to study Arctic sand mites. There's no set path to becoming a scientist. If you haven't seen it already, you'll notice that many successful professors haven't had "linear" careers, though nonlinearity is more common in some fields than others.

Similarly, don't argue that the fact that you got an A+ in ReallyHardUpperLevelScienceCourse, scored perfectly on a standardized test, or had an IQ of 155 at age 10 means you're qualified to be a scientist. (I've seen the last one, though the numbers have been changed to protect the naïve.) First, your recent grades and scores will speak for themselves, and only your parents continue to find your childhood adorable. Second, the argument suggests a belief that scientists are born more than they are made. It's far better to describe how you've pushed yourself to learn particular skills--a talent required for a sustainable research career--than to say that you're smart. One could argue that the A students in particular need to show that they can push themselves, make mistakes, and learn.

The statement should mostly be about the ideas in the field that interest you and questions you'd like to investigate. It's fine to reference particularly germane papers that excite you (do not simply cite the most classic papers in the field that were assigned reading in undergrad), but you do not need to spell out a fixed plan of research for the next five years or cite for the sake of citing. Describing interesting questions in several thematically related areas is fine. Briefly describe how your past experiences have prepared you for research, and briefly discuss what attracts you to this particular program. That's it!

The writing should be extremely clear, but it does not need to be cute or clever. The quality of your writing matters; no adviser likes rewriting students' draft manuscripts. In my opinion, the sine qua non of writing advice remains Strunk & White's Elements of Style. I suspect every native English speaker either loves that book or has been conditioned through repeated exposures to ignore it; I wonder how many non-native English speakers know it and find it helpful. Working to improve your writing now is just win all around.

There's not much to sweat, really.

Keep in touch with the people who wrote your letters of recommendation

This is one of those things that seems increasingly obvious in retrospect, but I still understand why people don't do it.

If this isn't clear to you now, it will only be clearer with time: It's important to let the people who wrote you a letter of recommendation know how things are turning out. At minimum, send them a quick email to let them know where you've decided to go. If you don't know where you're going yet, email them to say where you've been accepted. Thank them again for their help. Keep it short and sweet.

Here's why this is important: Your letter writers care about you. They have invested time, energy, and potentially some of their reputation endorsing you. They care more now about your success now than before they wrote you a letter (this is called the Ben Franklin effect), and involving them in your success makes them happy... and more excited about helping you in the future.

As a high school student and undergrad, I remember being slightly terrified* asking people to write letters of recommendation. I'm sure I didn't follow up as thoroughly as I could have. I'm now in a place where I'm writing letters of recommendation for people applying to graduate programs. I ask all of them to let me know how things turn out and where they end up going. I think one student in a half-dozen actually wrote me six months later. She's in a closely related field, and I'd be happy to help her again in the future. (I feel less excited about the people who thanked me and told me they'd stay in touch and haven't.)

Writing a good letter of recommendation is hard. It takes just the right amount of specific, moderated hyperbole. Sometimes the writer is giving the subject the benefit of the doubt in a few areas; it sucks to be disappointed. I don't think I've ever spent less than two hours on a letter, and I know several professors who regularly commit evenings and Sunday afternoons to the task. They could've gone out with their kids for ice cream, but they decided to promote you instead. Help them feel good about the decision.

As long as you're not sending holiday-newsletter-worthy emails, you really can't lose on this one.

*Now I'm just vaguely queasy.

Pre-interview stuffs to do

For people who have interviews approaching, here's a short, preparatory (and probably mostly self-evident) checklist for the campus visits:

• If you haven't done this yet, check to see if it is traditional in the department for prospective students to contact potential advisers in advance of the interviews. In some departments (including the three I've been part of), it's really your future adviser who grants you admission, and the department just rubber-stamps their decision. In other places, it's common for students to join without knowing exactly who their adviser will be. Write your potential adviser, if it's appropriate.
• Read the departmental website thoroughly. Try to determine the requirements for achieving candidacy, what kinds of coursework students take, whether there are lab rotations or teaching requirements, and whether there are department-wide policies on how graduate students are funded.
• Read thoroughly the lab websites and personal websites of faculty with whom you are interviewing. Read their CVs. What are their academic backgrounds, and who were their advisers? What fields have the potential advisers published in, and which fields have they published in recently? Do they have tenure, and if not, when will they be up for it? (For outdated websites, you might want to supplement their publication list with searches on Google Scholar, PubMed, arXiv, Web of Knowledge/Science, Scopus, etc.).
• Scan the specialties of the faculty members in the department. Get a sense of the breadth of the department.
• For each faculty member with whom you have a decent chance of working, read the abstracts of all of their papers that you find vaguely interesting. Read thoroughly at least a few papers that relate to work you might do with them. If you don't have access to these papers through a university, it's perfectly fine to email the professor to ask for a "reprint" (which will really just be a pdf). It's better not to do this at the last minute.
• Scan the pages and publications of the grad students, techs, and postdocs in the labs you might join. 
• Figure out who the department chair is.
• Write a cribsheet with this information somewhere and take it with you to interviews. This is really helpful if you're interviewing at a bunch of places back to back.
• Review your personal statement, and use it to develop a list of questions in your field that you find interesting and another list of potential projects. These ideas don't have to be genuinely viable at this point, but they show you're curious and thinking about research, and you can use them as a springboard in conversation to talk about more realistic directions.
• Write down the questions you have about the department, research, etc. (See the posts on meetings with potential lab members and potential advisers for more ideas.)
• Take a notepad and pen with you to your interviews.

Bonus points:

• If your potential advisers are funded by the NSF, look up their current and past grants on the NSF's Fast Lane Award Search. If they're funded by the NIH, check out the NIH RePORTER database. Most private foundations have their own databases too. Sources of funding are usually listed on CVs.
• Look up your potential advisers' most cited publications in one of the citation databases mentioned above to get a semi-objective sense of what they're known for. Also look at who's citing some of their more recent publications--which hypotheses are being debated? Who are their collaborators? Pay attention to any Science, Nature, Cell, PNAS, and Phys Rev Letters publications.

 Are there other preparations that people have found helpful?

Following up after interviews

Thank everyone with whom you met for >15 min! This means graduate students, postdocs, faculty, and administrators.

A simple email should suffice. Following classic thank-you form, it's good to highlight what you particularly enjoyed about the conversation.

If you're thanking a potential adviser, the email should be a bit longer and touch on the research projects that interest you and (if true) the positive interactions you've had with other lab members. If the lab is your first choice, it's okay to say so. You can also gently remind the potential adviser about any outstanding questions he said he'd get back to you on.

If you want to write your letters by hand on your prettiest stationery, that's okay*--as long as they go out immediately. Assuming you have already written a decent note of some kind, the most important thing is that you send it quickly, ideally within 2-3 days of your visit. Snail mail has an obvious disadvantage here. Where I did my PhD, we gave feedback on the candidates several days after the campus visit. It's best if you can beat this deadline.

The whole thanking-people-for-meeting-with-you thing is a generally good habit for life.

*Keep in mind that a lot of researchers travel frequently and don't check their mailboxes that often. I'm one of those people who prefers having all my correspondence in one, easily searchable place (e.g., my gmail inbox, supplemented by tags and threads). Email might make a lot more sense.

What to wear

Disclaimer: I haven't seen any randomized, controlled studies that test the hypotheses (read: opinions) below.* That said, I've experienced both urban and rural academic environments in different parts of the country and in Europe, and I'm a fairly socially astute person. I've also worked in very formal professional environments. What I write below applies to science programs in the United States.

Looking too nice makes you look clueless. Looking too sloppy makes you look clueless too. The goal should be to dress slightly more cleanly, neatly, and smartly than the people with whom you'd be working.

Women are probably best off wearing slacks and a blouse +/- a sweater. Men should wear slacks and a shirt. No tie, unless one really makes you happy. Flat shoes are good for both sexes. Try to avoid conspicuous brands.

This stuff shouldn't matter, but it kind of does: I remember a grad student making light fun of an applicant's precociously blingy handbag. (This might not have happened if the applicant hadn't already displayed an attitude to match.)

Remember, you can dress almost** however you want when you're a grad student.

If you've never dressed for a professional job before, get someone else to judge your outfit. Ask them if you're "dressy casual."

If you're visiting a lab that works with a lot of doctors or industry types, people might dress more nicely, but probably not enough to affect the recommendations above. I've wondered about the labs at Mayo Clinic, which requires its medical residents to wear suits every day.

Lastly, if it's cold out, take a coat. If it might rain, take an umbrella. Wear shoes that allow you to walk several blocks to a restaurant. When you're famous and have tenure, it's okay to show up to give a talk in January in the Midwest without so much as a sweatshirt (true story). For interviews, you want people to focus on your words and fantastic attitude, not your social awareness or thermoregulatory abilities.

*The disclaimer applies to the entire blog, come to think of it.
**This is an interesting topic for another post.

The campus visit - part three

Perhaps the most exciting part of the visit is chatting with potential labmates.

You'll probably spend more time every day interacting with other grad students and postdocs in your lab than with your advisor. Your labmates are the people you'll first go to when you have an idea that might be the awesomest thing ever or really stupid and you need to check. They're probably following the literature more closely than your adviser, and they'll be the ones who forward you cool articles related to your work. They'll almost certainly be more familiar with the methods you're trying to use.

It's really important that you at least slightly like your labmates, on average.

Speaking from personal experience, a single curmudgeonly or even pathological labmate is endurable if you're surrounded by an otherwise happy, creative, and amiable group of people.

Talk to as many potential labmates as possible. Talk to them about their research, and see if the conversation takes off. You can also ask about the same topics you discuss with your potential adviser. How did they arrive at their current projects? How would they describe their adviser's mentoring style? What conferences have they been to? How's the funding situation? With whom do they collaborate in the lab, in the department, and at other schools?

The point isn't to search for dirt about the potential adviser or anyone else. That said, if a potential labmate makes any suggestive comments, follow up as tactfully as you can. Face-to-face conversations are practically the only option in this case. I was once in the awkward position of meeting with a potential advisee of a professor (not my adviser) who was severely negligent as a scientist and a mentor. The advisee didn't ask about the professor's advising habits or working style. I compromised by suggesting a few pseudo-reasons why another program might be a better fit.

My scientific development might owe more to a superfantastic labmate than to my adviser. This labmate was an extremely clever older grad student who decided early on to involve me in her brainstorming. She was generous and encouraging, and we wrote some kickass papers together.

Science is intensely collaborative, and the more you like your collaborators, the more fun it all is.

The campus visit - part two

In the last post, I suggested that you treat every encounter in your campus visit as an interview of sorts. There's a decent chance that even if you won't ultimately do your PhD near the person you're talking to, you'll run into each other again. But this doesn't need to give you performance anxiety.

The campus visit is a mutual opportunity: it's an opportunity for you to determine if you can see yourself happy in a particular lab or program, and it's an opportunity for others to assess if you'd be good to work with. If you show evidence of caring about just one side of the equation, that's a red flag.

Put differently, all of the conversations you have with grad students, postdocs, applicants, potential advisers (PAs), and other faculty members should acknowledge (for the most part implicitly) the concerns of each party. If the other person would make a good colleague, you should see a similar balance of issues reflected back.

In the next few posts, I'll describe how this concept plays out in the interviews. The focus of this post is the meeting(s) with your potential adviser. Remember that the meeting is a mutual assessment of character and a chance to compare goals and expectations. Be prepared, but don't try to impress or look good at all costs; focus instead on understanding your PA and being understood. (Also, remember that most scientists--at least the ones you'd want to work with--have pretty good b.s. detectors.)

Interviews with potential advisers
The fundamental question on your PA's mind is almost invariably, "Is this applicant going to help me accomplish my research?" All of the other questions below follow from this concern.

• Is she reliable? Will she meet her deadlines?
• Will he come running to me, asking for help the second something goes wrong, or will he persist and try to find the answer himself or from other lab members? 
• Is she tenacious? Can she handle failure and imperfection?
• Can he admit it when he doesn't know something? Can he acknowledge making mistakes? Does he demonstrate an ability to learn from mistakes?
• Is the applicant really interested in working here? Does she actually understand what we do? Does she understand the main questions in the field?
• Is the applicant really interested in becoming a researcher? Does he have realistic expectations for  graduate school?
• Is she creative and independent? Can I imagine her developing her own projects and eventually teaching me a few things?
• Is he going to contribute to the lab and program as a whole? Can other people discuss research with him, and is he generous with his time and ideas?

(I don't include questions of cognitive competence--if you've been invited to interview, you've almost certainly passed that bar.) Your questions about your PA will likely include:

• Does the PA show any indication of being a good potential mentor, or does he seem interested only in acquiring a lab hand? Does he show any interest in my interests and goals?
• How much does the PA actively promote her students and postdocs? Does she encourage them to attend conferences, give talks, network, and apply for grants? Does she compete with them for authorship or speaking slots? 
• Does my PA have the financial resources to be a good mentor? Specifically, does my PA (potentially in conjunction with the program) have the money to support me for five years? To support travel? How much of the support would be in the form of research assistantships, and how much in teaching assistantships? It's generally better to do less teaching and more research.
• Does the PA have the professional standing to be a good mentor? Does he have tenure? Does he have a history of funding and quality publications? (Note: I don't mean to imply that you shouldn't work with an untenured professor or someone who has received only one major grant, but it's important to realize that the risks are different. Untenured PAs might not receive tenure, especially at highly competitive institutions, and they might move. Sometimes students follow, but it's obviously complicated. Professors who lose their grants and fail to obtain new ones might have to downsize their labs.)
• How is my PA's research portfolio expected to change in the next few years? Am I interested in the upcoming projects, and would I have the opportunity to work on them?
• Does my PA have time for me, or is she too busy with other lab members, teaching, travel, etc.?
• Is the PA's mentoring style good for me? Is he a micromanager? Does he expect all of his students to work weekends? Does he expect students to develop all of their own projects from day 1? How much time could I spend on my own projects at different stages--will I be restricted to the work outlined in existing grants?

(I'm similarly assuming that by the campus interview, you've already made sure that your PA does good science that interests you.)

Many of these questions are best answered by talking to potential lab members. I'll get to those conversations in another post. Useful questions to ask your PA include:

• "What future projects do you have planned? Do you have any grants in review right now?" If they do, you can ask if they'd mind sharing the proposals. Note that you can probably obtain summaries of their currently funded grants online at institutional websites (e.g., NIH, NSF, the McDonnell Foundation, etc.) or on their CV.
• "Generally, what do you expect of your students in each year of their PhD program?" This is where you find out if the PA expects all students to have a paper submitted by the end of their first year (potentially a warning sign), not to have any papers submitted until their fifth year (also a warning sign), or to be teaching every year (which doesn't speak well of the funding environment).
• "What are your former PhD students and former postdocs doing now?" This is probably one of the most important questions to ask, assuming the information is not on the lab website. If the PA doesn't know, run. Otherwise, make sure that at least a few of the recent graduates are doing what you'd like to do after graduation, whether it be industry, government research, or academia. You can usually sense from the answer the PA's attitude toward non-academic jobs. If your PA is one of those go-ivory-or-go-home types, and you're ambivalent about being an academic, think very hard about whether you would be happy in that lab. There's a good chance that your priorities and interests will be increasingly misaligned with your adviser's, and your adviser's support is critical to your getting a job--not to mention staying happy and funded. 
• "How would you describe your mentoring style?" Cheesy but probably illuminating. I wish I had asked this one.
• "What kinds of conferences do your students go to?" Obviously, you can and should ask your PA's students, but here you can learn whether your adviser encourages students to attend conferences even when the student isn't presenting. These kinds of opportunities can be especially valuable when you're just entering a field and trying to figure out who's who and what the hot questions are. That a PA would support students in this way shows that the PA cares about the student's professional development and has sufficient resources.

Finally, be sure you enjoy talking with the PA on some level. When I was interviewing, one PA told me to choose a PhD adviser exceptionally carefully, because when I was done with my PhD, I'd be more like my adviser than my parents. This was only a slight overstatement.

The campus visit - part one

The most important thing to keep in mind when visiting potential PhD programs is that everyone you run into--including other applicants--might be a future colleague, and anyone in the department can probably have a say in your admission. There are plenty of other useful insights related to campus visits, but this is paramount. Be kind, respectful, and professional to everyone.

At my PhD program, the admissions committee asked faculty members, administrators, and graduate students to email our impressions of the applicants. This is where we would write that Jingfei seemed very familiar with the methodological challenges of researching metabolic pathways in green jujubes, and that we were able to talk effortlessly for an hour with Carlos about recently published studies on catalytic nanostuffs. Even in programs that might not formally solicit feedback, you can bet that people confer. Below are some of the less positive comments I've heard:

• (By far the most common:) The student seemed full of himself. He was more interested in describing his accomplishments and abilities than learning about research in our lab.
• She had no clue about the basics of our work. It's not clear why she's applying to our lab/program.
• When talking with him, it was not obvious what excites him about research or why he is pursuing science as a career.
• She was a little lame for not going to the evening social.

The last comment was actually made by a faculty member in my department. The committee fortunately dismissed the criticism as irrelevant. The comment does, however, highlight that people will be evaluating you not only for your scientific potential but also for what kind of colleague they think you would make. Your character matters. I'll discuss this in more detail in another post.

What other applicants think of you obviously won't have a huge effect on your chances of admission, but it's still useful to think of the other prospective students as future colleagues and potential collaborators. I know two people who met as applicants at one school, earned their PhDs at two other schools, and now occasionally review each other's grants and manuscripts as faculty at different universities. It's a smaller world than you might think.