Friday, October 02, 2009

On Being Narrow

In a tweet a few days ago, David Bacon
wonders why everyone always assumes all he can do is quantum computing? Oh, because that's all he's done. Time to do something new?
What David (aka the Quantum Pontiff) says can apply to any discipline. Are you a narrow researcher? Take my simple one question test.
Do all your co-authors know each other?
Being narrow has some advantages but mostly disadvantages.
  • You can really know an area. Particularly in a field like quantum computing which has steep learning curve before you can become and remain an active researcher. 
  • Your are part of a very tight community. These people know you well. You look forward to seeing them at workshops and conferences. They can write you wonderful recommendation letters (and vice versa).
  • On the flip side, you don't know many outside your research area and they don't know you. 
  • Narrow researchers often lose themselves in the minutiae of the field, looking at questions whose importance seems obvious from those inside the field but impossible to explain to outsiders.
  • You tend to go to smaller and focused workshops and conferences because the majority of the broader meetings have little that interest you. This further isolates you from the larger community.
  • As David laments, others view you as focused and unable to solve problems outside your field.
  • As your field loses importance, so do you.
  • There are fewer grant programs you can apply to, and you have co-authored with most of the people who could properly evaluate your research, making them ineligible to review your proposals.
It's fine for a graduate student to remain focused for their dissertation research. But even then best to take advantage of your university's offerings and take courses in a broad range of topics. As a post-doc or young assistant professor, you should talk to other professors and ask them about their problems. You'd be surprised how much the tools, models and techniques of one field can apply in another. But be careful, others get upset if you try and impose your field's beliefs on their fields. 

Many successful senior researchers will completely change fields a few times in their career, taking a year or more off, maybe during as Sabbatical, to learn the background and important problems of another area and then start tackling those questions.


  1. Many successful senior researchers will completely change fields a few times in their career, taking a year or more off, maybe during as Sabbatical, to learn the background and important problems of another area and then start tackling those questions.

    Cynthia Dwork once suggested to me it's a good idea to change areas every ten years or so; I believe the main points were it gives you the chance to engage new and interesting questions, and forces you to move from an area in which you may have grown too comfortable. Given her success in tackling privacy (as well as her other successes!) I'd say it's an idea to be taken seriously, though I admit I personally find it hard to let go of the old stuff. (Every time I think I've written my last paper involving the power of two choices, my thesis topic, I seem to get pulled back in...)

  2. Quantum computing is an interesting field to use as an example. First, I don't think that there is much of a learning curve. You have to learn quantum mechanics, which perhaps is a steep curve coming from a CS background but is a given if you come from physics, but after that you can apply large amounts of your previous knowledge to different problems.

    Also, quantum computing isn't just 1 field. A very partial list of different subfields: quantum algorithms; quantum error correction; quantum channel capacity; entanglement properties of physical systems; lower bounds and complexity theory; etc...

    That list of subfields stuck to the more theoretical subfields, as that is what I thought would interest a theoretical computer scientist, but of course implementation in superconducting systems, ions, cold atoms, spins, and topological qubits comprise several more areas of research.

    And here's my contention: quantum algorithms, for example, is as different from quantum error correction as a field, as algorithms is from error correction in the classical CS context. So, I think someone could easily spend their career doing quantum stuff and be as broad as someone who work on new classical algorithms and worked on classical information theory and worked on lower bounds...i.e., as broad as someone working in several major different fields of classical computer science. In fact, quantum encourages breadth.

  3. I think this post is too simplistic, since it ignores most of the benefits of being narrow, especially early in your career. If you branch out too soon, you will not get hired. Dwork's advice, to change areas every ten years, is more realistic.

    Is it better to have many ideas in one area, or one good idea that applies to many areas?

  4. 1) Much harder to change fields in Math since its been around longer (thousands of years longer?) and hence has a steep learning curve.
    But see point 2.

    2) If you change fields but your new field still uses some of your old field,
    thats makes it easier.

    3) When you are young you should be some narrow in what you PUBLISH but your knowledge base BROAD so that you can change fields later.

  5. Hamming recommended "Somewhere around every seven years make a significant, if not complete, shift in your field. Thus, I shifted from numerical analysis, to hardware, to software, and so on, periodically, because you tend to use up your ideas."

    So Cynthia and Lance are in excellent company. :)

  6. Is it better to have many ideas in one area, or one good idea that applies to many areas?

    It's better to have many ideas in many areas.

    Being narrow/over-specialized at any point of your career expresses both insecurity and inability to relate to a field that it's not that large anyways.

  7. Given ongoing developments in mathematics, science, and engineering, can't we take it for granted that *everyone* will be adapting their career focus?

    Here is one (of many) thought-provoking quotations relating to career changes:

    @book{ Author = {Neil Sheehan}, Publisher = {Random House}, Title = {A Fiery Peace in a Cold War: Bernard Schriever and the Ultimate Weapon}, Year = {2009}, Annote = {p. 182:``While von Neumann still kept his hand in at pure mathematics by doing an occasional proof, he had long since become bored with the abstract realm of mathematical research. He was instead dedicating his nonpareil mind to the practical applications of mathematics and mathematical physics to the service of the American State, first during the Second World War and now in its contest with the Soviet enemy. With the exception of the Coast Guard, no American military or intelligence organization existed that John von Neumann did not advise.''}}