I have spent most of the last few days transfixed by events in Iran. Twitter has proven to be useful for the first time in my experience. The situation is still unfolding and here are the main links I am using:

http://andrewsullivan.theatlantic.com/the_daily_dish/

http://twitter.com/TehranBureau

http://thelede.blogs.nytimes.com/

Readerless publications « Algorithmic Game Theory

by Noam Nisan deals with a subject about which I often complain. Check out the discussion on Noam’s blog, which I read regularly and is of very high quality. His recent post on correlated equilibria was the best explanation I have seen.

Annals of Innovation: How David Beats Goliath: Reporting & Essays: The New Yorker

by Malcolm Gladwell discusses how underdogs have done well by refusing to play the game as the stronger player wants (seems rather obvious, but the article presents lots of nice details).  Another recent excellent article showing how thinking harder and thinking negatively can improve outcomes is The No-Stats All-Star by Michael Lewis.

Of course this just illustrates the fundamental tension between amateur (in the sense of John Gielgud’s character in the movie Chariots of Fire) and  professional (in the sense of Harold Abrahams in that film). In the 19th century, it was common to accept any sacrifice by an opponent in chess, as in the spirit of the game. Later, it was realised that winning meant not playing the way an opponent might want you to, even if you had to grovel for a while.

If utility is completely represented by payoff for winning, then it is rational to play ugly. But otherwise, maybe not.

I have recently made some critical comments on blogs in the “theoretical computer science” area. One feature of blogs is that they encourage rapid dissemination. Unfortunately it is easy to write inaccurately, and I don’t want to offend unnecessarily. So here is an attempt to set out the argument better. It is an opinion, based on a few years of observation, but I don’t claim to be able to convince anyone by proof. I spent a relatively long time to write it, and now need to get back to doing research instead of talking about it!

Background: I come from a pure math (abstract algebra) background, moved into combinatorics (mostly generating functions) and also like to work on social choice and analysis of algorithms. I work in a computer science department and teach courses in “theoretical computer science”, mostly algorithms. I have enjoyed learning what little I know now about TCS, but I still consider myself primarily a mathematician.

I have no problem with considering “theoretical computer science” as a branch of mathematics, judged by mathematical standards. However it seems that the TCS community overall doesn’t like to do this, preferring to be considered part of computer science (whatever the latter is, but no time to debate that now). It isn’t clear to me why there even needs to be a separate branch (I don’t really understand “theoretical physics” either). A better classification would be based on the problems studied, not the methodology.

However, given this classification I see some strange features of TCS practice. These observations are not unique to me. Michael Mitzenmacher has discussed some of them in detail in his blog.

• Too much publication of too few results (an argument strongly made in recent years by Neal Koblitz among others). TCS researchers seem to publish more than mathematicians, and it is very noticeable that they publish many more conference papers and relatively few in journals (broadly speaking, the latter take longer to produce and involve more stringent refereeing, and tend to have fewer errors and omissions). This may not be bad for science overall (as argued often by Michael Mitzenmacher) but it surely makes it difficult when comparing the performance of researchers. Why not publish in a journal with tougher standards of peer review? Blogs, the arXiv, etc all exist, so dissemination of ideas is fairly easy these days – is it necessary to claim that conference presentations really count as publications? I find it particularly annoying that people claim that a journal paper that is a minor variation on a conference paper should also be counted as another publication. Of course, they never admit the “minor” part.
• Not much link between theory and practice. Theoretical computer scientists prove a lot of theorems, but the mathematical depth of a lot of the papers is not particularly high, in my opinion, compared to what mathematicians publish (and less checking goes on in conference refereeing than for journals). That would be absolutely fine if the papers were also subjected to empirical testing. But how many researchers who devise new algorithms actually have them implemented (if not themselves, by a student, for example)? (This has also been well discussed at My Biased Coin). I find the term “theoretical computer science” a little strange. It should be balanced by “experimental computer science”. Despite the major article in CACM on this (Nov 2007), it is far from clear that such a subject is thriving. Some areas, such as computational complexity, are very hard to test empirically – a result saying that a certain problem is NP-hard doesn’t generate many testable hypotheses, at least not in my brain.
• Very little attempt at popularization. David Harel’s book Computers Ltd is one of small handful of popular books about big ideas in computer science. Contrast this with the huge number of popular books on (often quite difficult) mathematics. In fact the whole idea that “Computer Science” is a science is not really understood by the public – many conflate it with “I.T.” and the engineering aspects. Given the lack of scientific method discussed above, perhaps this is a fair reflection of reality – but it shouldn’t be.
• Not much linkage with other areas of CS. I have too many colleagues who don’t know the difference between big-O and big-Omega. Few of them, if any, care about TCS enough to attend a seminar or even a public talk on algorithms given by a great speaker like Bernard Chazelle. And yet TCS ideas are essential for progress in many areas of CS, I have no doubt. This is of course not simply the fault of people in TCS, but in CS generally.
• Not very unified for such a young field. It looks to me as though “theoretical computer science” roughly encompasses computational complexity (classifying the difficulty of problems), algorithms (finding solutions to problems), and logic/semantics/programming languages. It seems that the last topic has relatively little coverage in the USA (see the comments at Computational Complexity); the first has advanced to a degree that is mostly very far removed from any sort of application (the models it uses are also suspect), and probably should be judged by the standards of mathematicians (in which case it might not do as well as it has to date); the second is mostly split between people who devise complicated (never implemented) algorithms, with basic big-O analysis only,and obsession over the worst case (predominant in the USA), those who analyze to death rather simple algorithms using heavier machinery and “average case” (always the uniform distribution, and more common outside the USA), and those who do experimental analysis (a seemingly small and not well regarded part of the overall community). There is little interaction between these groups. Division of labour is fine – the same person doesn’t have to prove lower bounds, then devise a nice algorithm, then analyse it in Knuth style, then implement it. But these people should be talking more, and it is time to ensure that more progress is made, more efficiently.

50 Years of Stupid Grammar Advice
at ChronicleReview.com gives Strunk and White (which I have never read) a hammering. It’s good to be reminded that those who care about accurate use of language (as I do) also need to know what they are talking about!

Peter Singer in America’s Shame has many interesting observations, relevant to all of us in developed countries.

“But how great should the contrast be between what we are prepared to spend to save an American life and what we are prepared to spend to save the life of someone in another country? A hundred times greater? A thousand times greater? Ten thousand times greater? The last of those figures seems to be the current approximate ratio, and that should make us uncomfortable.”

“In four surveys that asked Americans what portion of government spending goes to foreign aid, the median answers ranged from 15 percent to 20 percent. The correct answer is less than 1 percent.”

No real surprise, but the extent of this problem is surprising to me: according to a paper by Ralph L. Keeney, almost 45% of deaths in the USA are due to clearly poor decisions about smoking, other alcohol, illegal drugs, diet, exercise, driving, etc. Thanks to Michael Trick’s blog for this pointer. Rejoinders to this paper are also available at OR Forum.

I would like to see detailed discussion of the effect of alcohol on premature death and disability. Living in a country where basic social interaction seems to involve alcohol to a ridiculous degree, I have often felt that the downside of its consumption is overlooked here. Perhaps this is now changing – I am now seeing articles on the bad effects of binge drinking, and Parliament is considering a reversal of the drop in the legal drinking age. Let’s hope that evidence-based policy will result.

I found this article from The Press while searching the Internet to see whether I was the only one annoyed at the National Party billboards around town (it’s election season in NZ now). One such billboard says “More doctors. More nurses. Less bureaucrats.” One of my senior colleagues doesn’t seem to know the distinction between “less” (a smaller amount of an uncountable noun) and “fewer” (a small number of a countable noun), but since he also doesn’t know the difference between “criterion” and “criteria”, I assumed that it was just isolated ignorance. However a major political party presumably knows it target audience well enough to mimic their speech, so I got more concerned. The Press article also seems to indicate that “fewer” is not as commonly used as I had thought.

The distinction seems to have been formalized only about 1770. It is a useful one. For example, “less qualified nurses are being hired” is confusing (unless we write “less-qualified nurses” to describe nurses of lower skill level). I don’t think it is the most essential distinction to make in English, but I also doubt that the distinction is being lost (as this seems to suggest) because of principled reasoning. I suspect the main reason for decline is purely ignorance that there even is a distinction. If you have fewer distinctions that you know how to make in your language, it becomes harder to think in a nuanced manner. I also want to know whether those not using “fewer” ever use the word “few” – I am all for changes that make language more logical, but removing an obvious comparative doesn’t seem to fall into that category.