A downside to double blind review

January 27th, 2012 1 comment

A discussion started by Daniel Lemire reminded me of this issue. I recently participated in refereeing for a CS conference using double-blind review. I noticed an issue that I have not seen mentioned before (for example in the IMS Ad Hoc committee report). Several papers were not accepted, but they had some good ideas. If I now write a paper building on these ideas, I have no idea whom to cite or credit. I suppose I could ask the programme chair to put us in contact, but of course that may not occur for a long time (especially given the speed at which I can write papers these days). Still, this seems an obvious drawback not shared by single-blind review.

Categories: Opinion, Professional Tags:

Prometheus

January 18th, 2012 2 comments

I don’t claim to resemble him in every way, but his unfortunate fate came to mind in the last few months as I suffered from recurrent corneal erosion. A short description: imagine that intermittently 10-20% of the skin of your leg is torn off, and grows back within a few days. Now imagine that instead of the leg, it is in fact your cornea, it only happens at night, and it is your own eyelid that is sticking to the cornea and tearing off the top layer. This is certainly the most annoying, painful and debilitating condition I have come across that is essentially trivial in that it won’t really cause any permanent damage. Doing anything with the eye for hours or days after an attack is very difficult, and for me going an hour without reading is very unusual, let alone several days.

Apparently there is a good chance of simple treatment succeeding, and more complicated options exist.

Categories: Opinion Tags:

Trip to Iran

January 15th, 2012 No comments

I have just returned home after 5 weeks in Iran, mostly for a family vacation. There were many interesting experiences, a lot of them positive. Skiing at about the height of Mt Cook just a few minutes from the city was a lot of fun, as was a bus trip to the ancient city of Kashan, which has had inhabitants nearby for the last 8000 years. Meeting relatives (by marriage) and some old and new friends, buying bread from the neighbourhood bakery, and eating the very high quality and cheap pastries were other highlights.

Of course the political and economic situation is very bad and getting worse. Taxi drivers (of whom we used a very large number – no way was I going to try driving for reasons discussed below, and buses are not that convenient) almost uniformly blamed the government and had no faith in the idea of an Islamic Republic. The rial depreciated sharply against the US dollar and other currencies during our trip. The government appears to be using the strategy of internet “filtering” (censorship) to avoid discussion of anything important, although as usual they were not very competent: the NZ Herald newspaper website was unavailable, although the NY Times was easily accessible. Most internet-savvy people I met were well aware of how to bypass the filters. The drawback is that speeds are reduced to the point where some services don’t really work (I couldn’t see anything on Youtube).

Iran seems to be the opposite of Sweden in the area of design. Doorhandles are loose and when tightened, the locks no longer work. Light switches are routinely dangling from the wall with wiring exposed. Quality control in building seems to be an exception.

Tehran seems to be one big health and safety violation. Some of the highlights I noticed: most taxi drivers have disabled the seatbelts in the back, and seem bemused or offended if this is pointed out (my favourite was the guy who said he would drive carefully and slowly on our trip home, although most of the trip was on the motorway); exposed wiring is visible in many public places; construction workers using welding torches with no eye protection. The most obvious health hazard is the foul stinking air which at this time of year is at its worst.

Many of the health hazards are traffic related (my guess is that the major contribution to the air pollution comes from vehicles, many of which seem to be of low quality and run on low grade fuel). The lane markings are completely ignored, and traffic proceeds (slowly in most places) by a process of everyone trying to claim the right of way and then negotiating silently with the other drivers, who by now are within a few centimetres of the car, approaching at an arbitrary angle. Apparently Iran has 4 times the death rate from traffic accidents that NZ has. We only saw a couple of accidents while there. The low speeds in Tehran must make fatal accidents less common, so I wonder how bad it must be in other places.

This leads to the idea of the rule of law, and the difference between writing laws and enforcing them. Particularly local government rules on footpaths, essentially none of which are wheelchair accessible in the hilly areas because they have steps every few metres (presumably each household deals with its own vehicle crossing and no one checks that they mesh together into a usable path).

It is hard to escape the conclusion that a country with a lot of natural resources, great potential for tourism, a strong and enduring culture with (as yet) strong family units, is being let down by an appallingly bad governance system. I don’t subscribe to the view that just because they have never had a decent government in 2500 years, they can’t have one now, but it does seem that a culture change is needed. Judging from some academic and industry contacts we made, it seems that this change is under way a lot faster than we expected in some sectors, but it seems it will still take considerable time.

Categories: Opinion Tags:

2011 referendum simulator: experience so far

September 27th, 2011 1 comment

Several months ago I realized that the 2011 referendum in NZ on the voting system for parliamentary elections was coming soon. Geoff Pritchard and I developed a simulator with the aim of enabling voters to understand the consequences of a change to another system. In order to do this in a way that is useful to the non-expert, some simplifying assumptions must be made. We had substantial media coverage and some criticism.

Initial surprises:

  • How few people bothered to read the detailed FAQ before criticizing.
  • How many people thought that the simulator was trying to “back-cast” historical elections, and were certain that our results were unrealistic, without giving any evidence.
  • How much the criticisms, even unfounded ones, helped to clarify my understanding of what we had actually done, and suggested further research.
  • How short the attention span of internet visitors is.

In particular I want to respond to comments by David Farrar on his well-known site Kiwiblog. The relevant extract:

Now in 2002 National actually won 21 electorate seats out of 69 or 70. So this model is saying if there were 50 extra electorate seats, National would win 11 fewer seats!!

Why? Because they have come up with a formula based on the last 50 years or so of FPP elections, which they applied to the party vote figures for 2002. They ignored the actual electorate vote. It is a classic academic approach.

The more pragmatic approach, which is what others have done, is to say well if National won 21 electorate seats in 2002 out of 70, then if there 120 seats, their estimated number of seats would be 21*120/70, which is 36 seats.

In fact we did not look at any of the historical FPP elections The “formula” is based completely on the MMP party vote from the 2008 election (so yes, we did ignore the electorate vote, for what we think are good reasons).

However this got me thinking about how we might try to validate our assumptions. One way which I don’t (yet) claim is rigorous, but makes at least as much sense as the above, is to apply the simulator (the FPP part) to the historical FPP elections, and scale the 120 seats down to whatever it was historically (80 for many years, then increasing over time). The results surprised me greatly, as they are much better than expected, and this cries out for explanation (“further research”, always good for academics). Here they are. Note that these simulator results explicitly do not use any historical data, seat boundaries and parties have changed, etc.

1969: Real result was Nat 45 Lab 39; simulator scaled was Nat 46.9, Lab 37.1
1972: Real was Nat 55 Lab 32; simulator scaled was Nat 54.4, Lab 31.6
1975: Real was Nat 55 Lab 32; simulator scaled was Nat 55.1, Lab 31.9
1978: Real was Nat 51  Lab 40 SoCred 1; simulator scaled was Nat  47.5, Lab 44.5.
1981: Real was Nat 47 Lab 43 SoCred 2; simulator scaled was Nat 48.3, Lab 43.7
1984: Real was Nat 37 Lab 56 SoCred 2; simulator scaled was Nat 37 Lab 58.
1987: Real was Lab 57, Nat 40; simulator scaled was Lab 50.2, Nat 46.8
1990: Real was  Nat 67, Lab 29, NewLab 1; simulator scaled was Nat 71, Lab 26
1993: Real was Nat 50, Lab 45,  NZF 2, Alliance 2; simulator scaled was Nat 53.6, Lab 45.4

Categories: Public, Social Choice Tags:

Big O(micron) and Big Omega and Big Theta

September 27th, 2011 1 comment

Teaching an algorithms course recently, I realized that the correct use of these asymptotic notations is apparently rather difficult for students to grasp. In fact, I have some colleagues whose understanding of these concepts is not maximally clear.

In 1976 Donald Knuth published an article explaining these notations in detail and recommending their use. After 35 years and plenty of evidence that it works well, we still have resistance. Perhaps one reason is that the idea of “asymptotically equivalent to”, or “of the exact order of”  is formalized by the symbol Theta, while O is a simpler and more familiar symbol that evokes the word “order”. The most common misuse I have seen is exactly this use of O when Theta is meant. The principle that the most important and useful concepts should have the simplest notation implies that O would be better for computer science use. However, that would make it inconsistent with mathematical use where big-O is definitely used for upper bounds only.

The main mistake seen (also mentioned by Knuth) apart from the perhaps excusable one above is not excusable: it is the use of O to discuss lower bounds as in the example: “Algorithm A is better than Algorithm B because A is known to  run in time O(n log n) and B in time O(n^2)”. If O is replaced by Theta, then this might make sense, but the literature is full of algorithms whose O-bounds are not asymptotically tight – how do we know B doesn’t run in time O(n) also? Again, if you think that O means Theta, this mistake is an easy one to make.

Moshe Vardi on CS conference talks

September 19th, 2011 No comments

In CACM, Moshe Vardi opines that conference talks must be improved by force, in order to justify even having a physical conference. I have long shared this opinion, although the CS talks I have heard seem better overall than the ones I recall hearing in mathematics conferences. Lance Fortnow thinks conferences as a means of scoring publication credit must give way to their core function of promoting discussion and dissemination, while journals assume the other function. I definitely agree with this.

Categories: Professional Tags:

Southern Hemisphere Summer Scholarships

September 11th, 2011 No comments

(From University of Auckland science faculty . Anyone seriously interested in working with me should contact me directly. I have several ideas available).

The Faculty has the opportunity to access 100 Summer Scholarships funded by the university (as opposed to Faculty funds) for special categories of students–this includes international students. The Faculty management team has agreed that we should use our recent Northern Hemisphere summer scholarship experience to try to win up to 20 of these scholarships for international students to come over the NZ summer.

The terms of the scholarships will be as for the normal Summer Scholarship: targeting final year undergraduate students; $5000, plus $1000 available for expenses to the host. No costs to the hosting Department or supervising academic are incurred. The student is responsible for all fares, accommodation, etc. Scholarship to be paid as $3500 on arrival, $1500 on presentation of final report. We are preparing an advertising poster for (southern hemisphere) universities now.

Our Northern Hemisphere scholarship experience showed that these scholarships are extremely useful for academics wishing to enhance links with overseas groups, by providing funding for a student from a collaborating group to come to New Zealand for a short period.

Categories: Research Tags:

AAMAS 2012

September 11th, 2011 No comments

It looks as though I will be a (junior) PC member (= referee/reviewer).

Details:

AAMAS will be co-located with EC next year, June 4-8, 2012, Valencia, Spain.  Among other topics the CFP includes

4. Social choice theory
5. Voting protocols

Electronic Abstract Submission: October 7, 2011 (11:59 PM HST)
Full Paper Submission: October 12, 2011 (11:59 PM HST)

more info at

http://aamas2012.webs.upv.es

Categories: Research Tags:

A token humour post

August 11th, 2011 No comments

I found this funny, and depressingly familiar.

Categories: Fun Tags:

Useful survey of university rankings

July 1st, 2011 No comments

The European University Association has published a report which is a good starting point for anyone interested in the topic. I noticed one omission from their rankings: the UWA “High Impact Universities” which seems rather transparent.

Categories: Opinion, Professional Tags: