Professors in the sciences have research groups. The groups range from small (the professor and just one or two additional people), to sizable operations (a dozen or two) and sometimes mega groups (even I have heard of Langer’s mega group at MIT, even though I have nothing to do with that field).
Today someone said that being small and having impact are mutually exclusive. The exact words were that it’s unrealistic or even impossible to achieve certain lofty research goals with a small group, and that if you were ambitious you would obviously want a larger operation.
I both agree and disagree.
We recently hired some excellent junior faculty. They are doing really great but their groups are not giant, at least not yet. They are working well with their students, building up expertise in the lab, and ramping up to publishing their first independent papers. They are NOT lacking in ambition.
My group is sizable for a theorist in my field (usually 6-8 graduate students, 1-2 undergrads, maybe a postdoc), and is midsize for my department. There are people with bigger groups, but those those with groups significantly larger than mine are not numerous. I run a lean operation, but we do good work and we publish at a good rate. I think we are making an impact. I don’t know how much of an impact I would be having with a larger group. I know I would not have as much time with individual students or the ability to work on papers as much as I do now.
However, if you want to make a splash or pursue hot, fast-moving trends, you need a large group, with many highly qualified people. This modus operandi requires serious grant-writing abilities, and, depending on the agency, usually serious schmoozing abilities, as well. If you are like me and have a smaller group with mostly students, that means you cannot pursue fast-moving trends, but you can make an impact if you are thoughtful about the work you pursue, create a niche, and play to your strengths.
There is also variability across fields. One of my friends in applied math scoffs at the paper-production rate in another field as too high, with consecutive papers insufficiently different from one another or not having intellectual heft. It cuts the other way, too, when there are university-level awards, and being in a field where it is common to produce a lot and get large grants definitely looks much more dazzling than a thinner CV, populated by fewer (even if much longer and more “meaty”) papers and little grant money.
I feel that science could and should accommodate for different group styles. But it seems we have adopted enough quantitative metrics that are a proxy to impact but are really highly correlated with topical hotness and group productivity (counting grant dollars, citation numbers, h-index) that it is hard to see how it all doesn’t indicate that larger is better, as more smart people produce more per unit time than fewer. In many fields, especially lab-based ones, I feel it is becoming increasingly difficult to get a faculty job and keep the group going as a small-town grocer.
What say you, blogosphere? Are grocers out? Will they all be replaced by mega food chains? What are the strengths and weaknesses of the two modes of operation? Is one clearly better and not just what the funding agencies and citation metrics seem to lean toward?
xykademiqz 
Maybe the scientific impact of being a small (or medium)-town grocer is a longer term thing? It seems like with mega-groups I’ve known that people really got almost no time with “the boss” and its sometimes felt kind of like people were more data generators than scholars. Whereas with smaller groups I think there is more time for the PI to spend on the trainees “intellectual development “. Then maybe those trainees from the smaller groups are more likely to go on and be highly productive PI’s themselves? But maybe that’s more to do with the particular people than the size of the group.
I would think this is something that could be looked at with actual data?
The group where I did my phd grew from ~25 to ~40 over the time I was there, with about 1/3 of the trainees being post docs. Of all the students who graduated in that span, only two are now in faculty positions. There are a couple more in national labs (maybe 3) and I can think of three that went into post doc positions, which includes me.
I think almost all the post docs who passed through the group went on to tenure track positions,
I would say that most of the grad students compare favorably with the post docs in the group, in terms of creativity and intellectual capability and capacity to direct their own research direction, despite not getting much if any mentoring on the last skill. So, I don’t think my adviser is picking better post docs than the students he is graduating. In that sense, this could be a clear example of what jojo describes. I get the impression that when the group was smaller more of the students stayed in academia after graduation, maybe not in absolute numbers but in percentages. That seems likely to be an effect of mentoring differences. I have never gotten truly useful career advice from my adviser, partly because our infrequent meetings are always spent trying to get his feedback on research results or (lately) paper drafts.
The group continues to produce plenty of academic progeny, in the form of the post docs, so it’s not like there’s any real loss of influence that way. How much credit do silverbacks get for the rockstars that were their students versus the ones that were just their post docs?
I can say that while I might make more of an “impact” (whatever that means) if I had a big group, I would also be a lot less happy. One of the aspects I like about being a prof is working with my students. If I had a big group, I would have a lot less time to spend with each student. I really enjoy watching my students develop into scientists over time. I have 3-6 grad students + 2-4 undergrads at any given time, and that works for me. I have a good handle on their projects and also where they are as researchers.
I also would hate the extra schmoozing and trend-following required to get the funding required for a supergroup. So many of the “hot” papers turn out to be partially or completely incorrect, and supergroup management requires all the skills I pretty much lack. I like having my little niche where I can explore the interesting things I find while doing the bread and butter stuff required for my grants (which is mostly interesting, but would be different if I had completely free choice). So I’d say no. Small town grocers have their place.