Wednesday, August 29, 2018

Science and "Le Chateau"

I frequently see complaints on twitter about how awful academia can be: the grant-writing, the stress, the long hours, unappreciative undergraduates, faculty meetings, etc.  I'll acknowledge it can be rough at times (*see disclaimer below), and there are things I'd love to see changed. But I also don't want aspiring academics to get the wrong impression that it is all a horrible grind. As a counter-point, this post is meant to highlight some of the joys of academic science.

Last week I attended the Evolution meeting in Montpellier, France (** see second disclaimer below). While at the meeting, I stayed at a 200 year old Chateau. With gardens. On a winery.  It had turrets. It evoked a sense of grand history. The AirBnB Chateau was surprisingly cost-effective, by the way (just so you don't think I'm spendthrift): split among 7 of us, it was far cheaper than any of the hotels.

This isn't the first time I've had work trips that also included some sheer "this is awesome fun" elements. The "First European Speciation Conference" a few years back was at an imperial summer palace outside of Vienna, and they put us up at a 14th century castle of the Teutonic knights.  I've walked the beaches and rainforests of Brazil while at a conference, hiked in the mountains outside Banff, gone sea kayaking in Monterey Bay, hiked in the Rocky Mountains, and stayed at a Californian winery for a week with colleagues to write a grant proposal.  I've been to the concert halls of Vienna, and bicycled through the countryside of Sweden and Finland, walked around islands in northern France, went bird-watching in Okinawa. The list could go on... and Andrew Hendry could best me by miles, since he travels way more than I do (my kids are younger than his so I tend to say no to a lot of invitations to keep the family happy).
Mark Kirkpatrick checking out a dead penguin on a tropical Brazilian beach; Evolution 2015
Doug Futuyma catches a lizard while birding, Evolution 2015

The Schloss we stayed in for the First European Conference on Speciation in Vienna
Emperess Maria Teresa's bedroom and portrait in the Hapsburg's summer palace, now IIASA
Sushi with Jun Kitano's lab in Mishima Japan

All of which is to say, if you enjoy travel with friends to cool places, whether wild places outdoors, or places with rich culture or history,  then academia has amazing opportunities for adventure, travel, and exploration of new places you haven't been to. It is amazing fun, and a great perk of the job (*** see disclaimer 3).

Perhaps the most important point to make here, however, is that this isn't just about having fun. It's not a junket vacation at taxpayer's expense. The vast majority of the time on these trips is spent in intensive pursuit of science: seeing talks, planning projects, networking. These turn out to be perhaps the most scientifically productive and intense moments in one's academic year. And that's not just a coincidence. The setting of these meetings is itself a catalyst. As biologists, we are more creative and productive when we talk shop while strolling the beaches of Monterey or Brazil, than we could be sitting in a sterile hotel conference center.

So what exactly are the benefits of these long-distance academic trips?

First, you meet more new people the farther you travel from home. At the Montpellier Evolution meeting, for example, I got to network with European colleagues who I rarely if ever see on our own side of the pond. So right away the cost and hassle of the intercontinental flight has academic advantages. I talked about projects with people like Blake Matthews, Tobias Lenz, Daniel Berner, Katie Peichel,  and others who I rarely see. There may be papers or grants that emerge from that interaction, and hence from the travel. This is not just speculation on my part: a recent study quantified the value-added of going to conferences, as measured in collaborations and publications

Second, you encounter new biology that is the focus of our work and inspiration. At the Asilomar meeting of the American Society of Naturalists in 2018, Steve Brady and I spent a long time contemplating the behavior of kelp flies, something I'd never looked closely at before. Some day there may be a project to emerge from those observations. Here's a video of the kelp flies, in slow motion, scattering as you approach their shelter. They vary in when they fly away, and how quickly they return:

Third, you establish time in an inspiring place to have detailed conversations. Let's consider two examples:

In 2008, I had a 2-day meeting with Andrew Hendry, Katie Peichel, and Renaud Kaeuffler at the Hendry vineyard in California. We ran together in the mornings, workshopped our ideas and wrote during the day, and ate and drank good wine in the evenings. We had a definite goal, but also had great fun together, much like the recent Chateau picnic. In retrospect, that vineyard gathering was one of the more productive of my career: it led to two NSF grants (so far) and numerous exciting papers.

At the Montpellier meeting we had a picnic at the Chateau for a group of collaborators. Everyone brought some food: cheese, bread, fruit (the figs and plums were astonishing!), charcuterie (goose sausage!), apple tart, quiches, and of course wine from the winery we were on. A dozen people came. We brought the food out onto a table in the garden of the Chateau, set out chairs, and we sat around and ate and drank and planned a decade-long experiment that we are soon to start. Conversation was relaxed and good-humored.  The inspiring environment and food and wine were catalysts that stimulated thought, discussion, and helped bond together a group of people who would be working together intensively for years to come. If all goes to plan, in years to come when we celebrate a Science or Nature or American Naturalist paper emerging from our long slog of work ahead, we can raise a toast to the Chateau where the plans began to take a more definite shape, just as they had at the winery 10 years earlier.
The Chateau picnic

Wine from the Chateau winery. Its good.

Some of the collaborative team at the Chateau we rented
Talking science late into the night in the Chateau garden

All this travel, you see, can be both enjoyable and scientifically productive. In fact, I'd argue that the two go hand-in-hand. They are scientifically productive precisely because they are enjoyable. They help us let our hair down, so to speak, turn colleagues into friends, and free our minds from daily tasks to wander through though more creative spaces.

How to get the most out of a conference, according to Science:

* Disclaimer: I realize I am privileged to have avoided some of the rougher sides of academia, and some of that privilege is probably attributable to my gender, ethnicity, college experiences, and secure upbringing in an academic family that traveled the world (among other things).  

** Disclaimer 2: I realize I am also privileged to have been able to attend the meeting, whose attendance was capped and which is also not cheap especially for those of us coming from across the big pond. I organized a symposium (actually 3, all of which were accepted and I had to withdraw from being co-organizer on 2) and was chosen to talk, so that got me a guaranteed place in the queue to register. I'm at a career stage where I can afford to pay for this either from faculty travel grants (I used mine up for Asilomar back in January), grant funds (I prefer to use this to pay people or do science), or out of pocket (which is where this conference is making its dent, as I am between faculty jobs)

*** Disclaimer 3: Not everyone can partake equally of these perks. You need to get invited to many things, so you need to get to the stage where you are recognized enough to get the invitations. You need to have access to funds in one way or another to cover the costs, if they are not always paid (some are, some aren't). You need to be able to wait to get reimbursed for many things even when costs are covered. And you need to be in a personal position (health, family, etc) to travel. I am very lucky, for instance, to have an academic spouse who get the idea, and somewhat tolerant kids (stress on somewhat). I trade off a fair bit with my spouse when we each travel, though I do tend to travel more. But, there were periods when I couldn't travel because our kids were younger, and even now I follow a rule of no more than a trip per month, half that if possible.

Wednesday, August 22, 2018

Toward Professor-Student Interactions at Conferences that are Positive, Productive, and Comfortable

I am writing this post on a long flight home after the Evolution 2018 meeting in Montpellier, France. For the last day and a half of that meeting, I didn’t attend a single talk. I simply stood around in the booth area (near the publishers) and talked to whomever approached me and wanted to talk. This period was by far the most rewarding and productive time at a meeting, notwithstanding great talks and dinners and project planning meetings (OK, maybe the project planning meeting was even better!). I met old friends and made a bunch of new friends too, including many students and postdocs I had never met before. The informal setting was extremely conducive to discussions of just the right length at just the right frequency. This approach, which Dan Bolnick also adopted and loved, led us envision a few suggestions for students, Professors, and conference organizers regarding the best way to facilitate interactions. Of course, these new suggestions are in addition to the many other suggestions by others for how to facilitate positive interactions.

Suggestions for students:

Just walk up and introduce yourself! Believe it or not, most Professors are just as nervous about approaching a student as a student is about approaching a Professor. If a Professor approaches a student, even at a poster, that Professor has no idea if the student is doing relevant work or even wants to talk to them – awkward! They would much rather have conversations with students who actually WANT to talk to them. And don’t worry about interrupting an ongoing conversation. Much of the time, Professors are just standing around – even when talking to their colleagues and friends – killing time. Much of the time they are even hoping that relevant students will approach them. If they are talking to someone else: Just say “Excuse me Professor XXXXX, I would love to chat with you when you have a chance” – and they will either say “Sure, how about now?” or “Great, how about in a few minutes, I just need to finish talking to XXXX.” And – often – Professors are quite happy to get out long conversations they have been having with someone, including their friends if they can talk someone new who clearly wants to talk to them.

As an aside, don’t stand around just outside the periphery of the conversation waiting waiting waiting, sort of trying to catch their eye but not really. In fact, the Professors are standing there wondering if you want to talk to them, but – since they aren’t sure – they aren’t going to ask. And they aren’t going to end their existing conversation if they aren’t sure you want to talk to them. It is just awkward all round. Just walk straight up, interrupt politely, and ask if you can chat. Then, if you have to wait, walk over and read the books until the Professor comes up to you.

Send Professors emails inviting them to your talk or poster. This can be a huge relief for a Professor as it gives them information, from a dizzying array of possible talks to attend or posters to visit, of a talk/poster that will be specifically relevant to their interests – and that will be given by someone who is specifically interested in talking with them. Some conferences, such as ESEB, already do poster invites, which is great, but I suggest a few other targeted emails regardless of those invites. But, of course, don’t just saturate the Professor pool – pick 4-5 that you would most like to have see your poster or talk.

If you have met the Professor before but don’t know them well. Pretty please give clues as to who you are and what you do. I am frequently approached by students who I know I have met before, but who I can’t remember precisely where or in what context. It is extremely awkward to admit you don’t remember someone who you have met before – or to have look at the name tag to get a clue as to the previous context – or to just stand there hoping to ask the right question that gives you the necessary prompt without letting on you don’t remember. Just walk up and say “Hello Professor XXXX, we met at the XXXX meeting in XXXX, I work on XXXX with Professor XXXX.”

As another aside, when Professors talk to you, their eyes will often dart around as though they are looking for some better to talk to. Most of the time, this isn’t it. They are indeed often looking for someone they know – but not to get out of the conversation with you but rather to make sure they don’t miss saying hello to someone who they need to talk to later.

If you are looking to end the conversation, just say “It was very nice to meet you, I have to go now to [the bathroom, my poster invites, a scheduled meeting, etc.]”

Suggestions for Professors:

Following the experience of Dan and I from this last conference, I highly recommend setting aside some time, perhaps a lot of it, to just stand around in a common area and thereby make yourself available for people to approach.

If you are comfortable doing so, send a tweet (if you tweet) saying where you will be and when and that you would love to talk to students or postdocs.
Stand up for this period. The informal nature of standing makes it much easier to be approached and for conversations to not be awkwardly long. Don’t stand around scanning the crowd looking for someone who might be looking for you. Just chill: browse the books, chat with friends, look at the posters, tweet, check email on your phone, etc.

If you are in a conversation with someone you know, and you are approached by someone else, consider the responses above: “Sure, how about now?” or “Great, how about in a few minutes, I just need to finish talking to XXXX.”

Try – to the extent possible – to pay attention to the person you are talking to rather than scanning the crowd around them for people you know. I realize this is very hard not to do but it makes the student feel like you are trying to get out of their conversation.

If you do see someone passing by and need to talk to them, apologize to the student, say you will be right back, and give only the briefest hello to the other person before heading back to the student. Of course, if you really do need to get out of the conversation try: “It was very nice to meet you, I have to go now to [the bathroom, my poster invites, a scheduled meeting, etc.]”

Conference organizers:

Efforts to facilitate Professor-student interactions through “speed dating” or “lunch discussions” or whatever are generally useful but, to be honest, they are a bit awkward. (Note: I am happy to keep doing them – so don’t hesitate to include me.) The Professor is usually talking to 4-5 different people doing very different things, and it is hard to have a decent conversation with any one of them. Instead, perhaps consider facilitating the “chill session” described above. That is, encourage Professors to make themselves available just standing around in some general area for a half-day of their choosing. Don’t schedule appointments for them with students, just make a general announcement that Professors standing around in that area are fair game – in fact they are there specifically hoping someone will come talk to them. However, the area should be one already frequented by others or having food, drinks, posters, exhibitors, etc. That way the Professor won’t be awkward “waiting” for someone to approach them but instead is just chilling looking at books, talking to publishers, and colleagues, perusing posters, or whatever. And happy to be interrupted!

That’s all for now. Consider giving it a try. And also note that much of this advice applies generally – that is, beyond Professors who are specifically and knowingly engaged in a “chill session.” Many of these tips for interaction will help in many conference contexts: poster sessions, hallways, receptions, banquets, etc. 

co-blogger's note from Dan Bolnick:
I wanted to add a couple comments after reading Andrew's post.
First, another reason faculty might be shy to approach you. I have a feeling this one will get a reaction: At the Evolution meeting I tried to go out of my way to introduce myself to strangers. Standing in the security line for the Corum, or waiting for drinks, I'd just introduce myself and ask about them and their work. It was fun and informative, but a couple of times, when the person I started talking to was a younger woman,  I had a nagging voice in my head saying "I hope they don't think I'm trying to be a creep". To be very clear: I wasn't.  But it did worry me, the optics of being a mid-career male just spontaneously striking up conversation with a female postdoc or grad student, no matter how good my intent. I don't want to be seen as a potential threat by someone who does not know me. Unfortunately, the fear of being misinterpreted is a deterrent to striking up a conversation, which is a problem in and of itself. That's exactly why I overcame my inherent introverted tendencies to start up conversations with strangers. I mention it just because it may be another reason why an older researcher might be shy, especially to strike up a conversation with someone who is a different gender.

Second: yes, Andrew's strategy involves missing talks. And yes, people will be disappointed if he's not in the audience. But there's only so much we can do. There were times when there were 5 simultaneous talks I wanted to see. Even if I went to talks non-stop every day of the meeting, I would miss the majority of talks that were of interest to me, and miss the majority of talks whose speakers might want me in the audience. As I reach the middle of my career (20 years since I started grad school, hopefully 25-30 more till I retire), I am more accepting of the things I cannot do. One of which is to see every talk. As I accept that, I increasingly am able to plan my meeting schedule with a balance of activities. And I agree with Andrew that the most scientifically rewarding things are the one-on-one or small group conversations where collaborations get planned, data gets analyzed, and schemes are hatched. I've sometimes wondered what it would be like to have a meeting with no talks at all, just conversation time about science. So, yes, I feel pangs of guilt about planning to miss a whole block of talks, but the benefits of extended face-to-face meetings are so large I'll deal with it, and I would have missed many talks no matter what.

Monday, August 6, 2018

On second thought...

I make a point of not writing too much about the behind-the scenes details of being an Editor, to respect the anonymity of authors, reviewers, and the process. But sometimes there are things which just aren't talked about openly but which prospective authors, especially students, need to know. So I'm going to spill some beans.

Let's talk about Editorial declines for a sec.

This is inspired by a particular paper, and I'm going to so totally change & obfuscate & rearrange the details that even the author in question probably won't realize this is about their manuscript.

An author submitted a paper to a journal I edit, which we will call Journal X.  I skimmed the paper in about 5 minutes (it was one of perhaps 4 new papers I was processing just that day). I was struck by two things. The author(s) were pushing an interesting conceptual idea I hadn't seen before, putting a twist on a familiar question of sympatric speciation (remember, I'm obscuring/changing the facts), by fusing that familiar topic with a new one (thermodynamics). And they did this with a really big-scale long-term experimental evolution dataset with unicorns. Impressive scope of the study. So, I passed it on to an Associate Editor. I confess I hadn't read it in detail, I just thought the dataset and question/answer sounded interesting, and worth a more careful look by someone who knows the detailed subject area better than I do, and has more time per paper than I do.  (Note: had I rejected it offhand, I certainly would have spent more than 5 minutes with it).

Now, we have a policy at Journal X. We want to give every paper a fair shake. But we also can't stretch our Associate Editors or reviewers too thin by assigning them too many papers. They get exhausted, they stop contributing decision recommendations or reviews, and we fall apart. So we try to avoid the situation where we send out a paper and get back an upset "why did you take up my time with this?"  Our policy is that the job of the Editor is to write helpful constructive reviews for Editorial Declines, for the papers that we shouldn't take our AE's time with. As my predecessor once told our AEs, "we Editors review some papers, so you don't have to". And our AEs should write reviews and recommend Editorial Declines for papers that aren't ready for reviewers' time. This is a favor to our reviewers, but also gives authors faster feedback than sending out a paper for full review. Sometimes my Editorial Decline letters can be pages long. The Journal X editors get thank-you letters for their detail, and for the fast turn-around (often just a few days). If you aren't going to get your paper accepted, wouldn't you rather get constructive feedback very quickly, so you can improve your paper for elsewhere?

The point is, we are trying to strike a balance between being fair to authors, and being considerate of AE and reviewers' time. That requires some triage, and a balancing act.

In the case of this particular manuscript about the thermodynamics of unicorn sympatric speciation, the Associate Editor gave a strong "Decline" recommendation, but acknowledged that I might disagree, leaving the door open a crack. That recommendation was supported by two full pages of the AE's own constructive review (that's not uncommon in the Journal X tradition). I was, frankly, surprised by the negative response because I thought the many-generation experimental evolution of unicorn mating behavior was pretty impressive. So I reread the paper, quickly but more thoroughly than last time. 30 pages in 20 minutes maybe. And I found myself generally agreeing with the AE. I wasn't 100% sure, but I want to respect the time and thought our AEs put in, so I took the AE suggestion and wrote a "Decline" letter and added my own two cents worth in to justify that on top of the AE's suggestions. I still had second thoughts, but I trusted the AE. (Note, at this point the paper had received about half an hour of my attention, and several hours of detailed examination by the AE, so this was not a casual decision by either of us).

Soon, I get a direct email from the Unicorn expert herself, thanking me for the detailed feedback but expressing her frustration. Not an appeal. Not a complaint. Just... disappointed.  She really wanted to publish with us.

I hate that part of the job, I don't like making people sad. I'm an author too of course, so I know how rejections feel. I had been rejected by Journal Y just that same day. So I was sympathetic.

A few days later, I did something I've not done before. Without an author's formal appeal, I went back and revisited my decision (I didn't tell the author, so as to not raise hopes). Remember, I had looked over the paper twice, once in about 5 minutes and once taking 20 minutes. So I hadn't fine-toothed combed through it (though the AE had). I can't, I often handle multiple papers per day (my record so far is 9). But this time, I had second thoughts. So I re-read the paper with the detail of a reviewer. I spent about 2-3 hours on it, and wrote down dozens of detailed and big-picture comments.  Had I erred with my Editorial Decline (with AE support)? Were we really wrong not to send the paper out to expert Unicorn biologists for review?

The short answer is, the paper really had a solid core. Unicorns really do undergo sympatric speciation. But we knew that already. The additional ideas that formed the centerpiece of the abstract, introduction, and discussion: the innovative fusing of sympatric speciation with thermodynamics? That was reaching too far beyond that solid core, and didn't have the data to back it up. Unsolicited, I sent the author an additional batch of my own detailed comments in an attempt to be constructive and further justify our decision, so they can really strengthen their submission for another journal.

<Note inserted later: The author replied, thanked me for the detail, commented it was more than she expected from an Editor. The author acknowledged that I had identified several weak points they had tried to gloss over, and that my assessment was correct and fair.>

The moral of the story here, if there is one, is this: we Editors do make knee-jerk decisions, but we do so in good faith trying to find papers we can support. And sometimes that makes you authors feel like we Editors are jerks. We can't read every word of every paper you submit, though we try to look through in enough detail to understand what you've done and what it implies. Consequently, we can indeed make mistakes. This fabricated case I refer to here is unusual because I double-checked myself in great detail, to see if I had erred.

That Editorial Decline? That turned out to be the right decision. Not because the author was a bad person or a bad scientist, its just that the paper needed work. It was claiming more than it had grounds to claim. With very substantial revision (reframing the point of the paper) that work would produce a fine paper, but not to the level of novelty our reviewers and readers expect of Journal X. The exciting integrative part had been more speculation than substance. So, my job was to help the author improve their paper to be a solid and successful submission to the Journal of Unicorn Biology. And the faster I could provide that feedback, the better for the author.

So, when you get an Editorial Decline, you may feel poorly served. Why didn't it at least get a review? I've certainly felt that way as an author. The answer is, I'd like to think that we Editors have a good  feel for what will fly with reviewers and readers, and what won't. As a junior faculty member I reviewed 7 papers for Journal X. As an Associate Editor I handled about 150 papers for Journal X. I've written 300 decision letters for Journal X since I started as Editor 7 months ago. I am overseeing about 35 active papers at the moment. All this gives me a clear snapshot of what reviewers tend to say, and where a given paper stands relative to other submissions in the competition for limited page space. I won't claim to be always right. But  I think I have a good basis for those decisions and will do my best to convey the justification. I emerged from this with a bit more confidence in the decision-making process. And I hope this story serves as a reminder to you, the readers, that Editorial declines (at least, with Journal X) aren't just arbitrary decisions, they represent the judgement of someone who has seen a lot of papers, and a lot of reviews, about where your paper falls in the discipline-wide multivariate distribution of papers (for clarity, quality, rigor, and novelty).

And if I have a second thought about a decision in the future? I'll still double-check to be sure I've been fair, but I'm growing (slowly) in my confidence about my judgements and slowly outgrowing the impostor syndrome of being Editor from Journal X.

Wednesday, August 1, 2018

Do certain subdisciplines lead to a higher H Index?

"Two roads diverged in an academic study. I took the one less-traveled by, and that has made all the difference [to my H-index]".  With apologies to Robert Frost.

Andrew just recently posted a blog here about H indices & how much weight to give them. I like his basic message that H indices, like the number of twitter followers you have, is best viewed as a measure of your H index, or your twitter presence, and not a fundamental metric of your worth as a scientist. I won't disagree. But, I will point out that for better or for worse, there are people who don't share Andrew's casual view. There are people who like metrics, and use them to do important things. Those people are sometimes called "administrators". And they do things like hire, promote, and dole out raises. So, it's not necessarily safe to dismiss H indices and the like, unless you can convince your local friendly bureaucrat to do the same. Good luck with that.

I recently had the dubious pleasure of being on the Merit Review Committee at my previous institution. We had a rubric that we used to judge our fellow faculty, based on publications (number, journals, citations), and grants received, students mentored, course evaluations, service, and such. This was used to rank faculty by three criteria. Perversely, research scores were used to judge who got a lighter teaching load. Total scores were used to dole out merit raises (we had no annual built-in cost of living increase to adjust for inflation, just merit raises). Now, we were given about two weeks to score 40ish faculty, just as the fall semester began. You can be sure we didn't read every paper that everyone produced in the previous year, let alone the past five years (our relevant period). We may look at some papers, but time is tight. Instead, we were given H indices and cumulative citations and numbers of papers published, both career-total and over the previous 5 years (so as to not favor older faculty). There's quite a range of H-values (to pick one of several possible metrics), which makes it very tempting as a tool for ranking our peers.

I want to raise three points now.

First, we really did look at the whole 5-year report, and rank people holistically. We didn't just use Excel to order people by their H index, or dollars earned, or the product of the two. We really were trying to be just, these are our friends and colleagues after all.

Second, we are aware that these indices can be biased by implicit (or explicit) bias within the research community, based on sex or ethnicity or sexual orientation. Andrew's excellent H-index (far greater than my own) probably does benefit from being a white male, and especially an outgoing and admittedly self-promoting white male.

Third, and what I really want to talk about here, is that these indices can vary by field. I noticed early on in my Merit Review involvement that some colleagues I really respect had much lower H-indices (and cumulative citations, total or 5-year) than others. I began to wonder how much that has to do with their sub-discipline of choice. For instance, there's a crazy ton of gut microbiome research out there today, so does studying that give you an edge? Certainly my own few gut microbiome papers (N = 4 so far) accrued citations at a much higher annual rate early on than most of my other papers. I voiced this issue out of concern that some of our colleagues were at a disadvantage in the H-index race, by their choice of topic. I was quickly shot down by a colleague who used the following argument: (I am paraphrasing)  on average the number of citations your paper accrues should be independent of field. Here's the math:

Let's assume that a discipline A publishes N_a papers per year. Discipline B publishes N_b papers per year. A is more popular than B, so N_a >> N_b. More gut microbiome papers than there are fish immunology papers.

Next, let's assume that the typical paper has R entries in its Literature Cited section. If you publish only in Nature or Science, R ~ 30; if in AmNat or Evolution or Ecology R ~ 80. To be flexible, we will acknowledge that each discipline has its own average number of citations per paper, R_a and R_b, but to start let's let R_a ~ R_b.

Okay, now the total number of entries in all Lit Cited sections of all papers in a field is N_a * R_a (for field A) and N_b*R_b for field B. These citations are to a smattering of other papers in the field.  To calculate the average number of citations to the typical paper, we just divide the total number of things cited by the number of things there are to cite. So in field A, the average paper gets cited N_a * R_a/ N_a times, which is just R_a.  And the average in field B = N_b*R_b / N_b = R_b.  So as long as fields A and B have similar caps in their Lit cited (R_a ~ R_b), they will have the same average citation rate. That's unrelated to the total number of papers in each discipline (popularity). Actually, it might even be better to publish in an unpopular field because popular topics get into Science and Nature and PNAS which slightly drive down R because of their more stringent caps on citations. The punch line here is, if you are an average author, your field shouldn't matter; you won't get cited much per year anyway (on average, R times per paper per year, times the number of papers you publish).

So, was my colleague right that H values and total citations are independent of discipline? Of course not, or I wouldn't be writing this. Let's forget the average for a minute and focus on the distribution. At a minimum, you could write a paper that nobody cited at all. Regardless of discipline. So your minimum citations per paper is zero. But your maximum, that's another story. If you publish in popular discipline A (remember, N_a >> N_b), maybe you'll do something brilliant and EVERYONE will cite you. So your maximum number of citations in a year, for that one great paper, is N_a.  In the other field, you could write the best paper ever and if EVERYONE cites you your total citations received is N_b. And we already said N_a >> N_b.  The punch line here is: if you are going to write an above-average paper, do so in a popular field, if you care about citation indices.

To summarize. Your average citations-received per paper should be independent of your discipline. But your highly-cited papers will be really really highly cited in a popular field, and ignored in an empty field. The tails of the distribution matter because we all write some below-average papers and some above-average papers, and it is the latter that drive the citation indices that our administrators use. The upshot is, when administrators use these indices they implicitly favor people contributing above-average papers to busy fields of study, over those contributing the best papers to sparse fields of study.  That's not necessarily wrong, but it certainly can stifle innovation and discourage people from forging their own path.

"Why'd you do it?"

One of the great benefits of academic life is that we are, to some degree, in control of our own time schedule. Sure, there are classes to t...