sciengineer

A pattern analysis of the second Rehnquist US Supreme Court

2006-01-30T20:13:00.000-06:00

That's the title of a paper by applied mathematician Lawrence Sirovich at the Mt Sinai School of Medicine in New York, published online on June 23, 2003. in the Proceedings of the National Academy of Sciences. It has already been the subject of a NYTimes article (four bucks or Times Select required).

[Note: I originally wrote this article in June 2003, just after the article was released. I think it would be interesting to do a similar analysis in the next few months on Judge Roberts and later Scalito.]

Its abstract : The second Rehnquist Court has remained unchanged in composition for 8 years, resulting in a large temporally stable database. This paper reports on a mathematically objective analysis of this ensemble of rulings aimed at extracting key patterns and latent information. Although the rulings of a nine-justice Court require representation in nine dimensions, smaller spaces describe the Court's actions; e.g., a 2D subspace describes the margins of all decisions, and use of Shannon information shows that the Court acts as if composed of 4.68 ideal justices. Comparison is also made with the 1959-1961 and 1967-1969 Warren Courts. Both Warren Courts have
remarkable parallels with the Rehnquist Court. In each instance, we present an optimal mapping of
the justices between the Courts, which underscores the similarity in the workings of seemingly dissimilar courts.

The full paper is available at the same site, but you'll need a subscription to get it. I'm lucky since I work at institution that subscribes to it, and thus have got and read the full paper. Sirovich's analysis is specifically devoid of any judicial/psychological/game-theoretic analysis. He deals with a simplified form of the process, where each judge says yes/no on the whole decision and the majority vote is the final opinion. As he admits, this does not take into account that a justice can vote differently on different parts of the whole case, but we have to start somewhere. Excluding such cases of split votes, an absent justice, lack of public information on who voted which way, and other ambiguities limits the analysis to 468 cases, about 70% of all decisions by the Supreme Court from 1994 to 2002/3.

Sirovich uses Singular Value Decomposition (SVD) analysis to find the two most important factor in making a decision. SVD is a tool for summarization, not prediction (in this case at least), i.e. it does not lend itself immediately to a method of predicting Supreme Court decisions beforehand. It turns out that nearly half (47%) of the court's decisions are unanimous (no-brainers perhaps?), and the first Sirovich dimension corresponds to this.

Kennedy +0.36
O'Connor +0.36
Souter +0.35
Rehnquist +0.35
Breyer +0.34
Ginsburg +0.33
Thomas +0.32
Scalia +0.31
Stevens +0.26

The second dimension is more interesting, being represented by the following weights :

Thomas +0.41
Scalia +0.40
Rehnquist +0.30
Kennedy +0.17
O'Connor +0.10
Souter -0.31
Breyer -0.33
Ginsburg -0.37
Stevens -0.45

Sirovich is careful not to draw any conclusions from his data that could be viewed as political. However, he has provided enough data for others to interpret, as we do here.

The weights of the second dimension correspond to the general perception of judges as liberal/conservative. Quoting from a CNN article of 10 July 2001, "Conventional wisdom divides the current Justices of the United States Supreme Court into three camps. First, there are the staunchly conservative Justices: Chief Justice William Rehnquist and Justices Antonin Scalia and Clarence Thomas. Second, there are the moderately conservative "swing" Justices, Sandra Day O'Connor and Anthony Kennedy. Finally, there are the moderately liberal Justices: John Paul Stevens, David Souter, Ruth Bader Ginsburg, and Stephen Breyer."

This is summarized in the table below (note the order), which has a few other details as well.

Judge	Public perception	Appointed
Thomas	very conservative	1991 (Bush Sr)
Scalia	very conservative	1986 (Reagan)
Rehnquist	very conservative	1972 (Nixon)
Kennedy	consersative	1988 (Reagan)
O'Connor	conservative	1981 (Reagan)
Souter	liberal	1990 (Bush Sr)
Breyer	liberal	1994 (Clinton)
Ginsburg	liberal	1993 (Clinton)
Stevens	liberal	1975 (Ford)

Sirovich's analysis finds that nearly all cases are summarizable by these two dimensions. Of course, SVD analysis focuses on trends, not subtleties. To continue the quote from Dorf's article, "These categories broadly describe the Justices' political views. Yet political ideology does not neatly translate into judicial philosophy, as was apparent in a number of the most interesting cases the Supreme Court decided over the past year. Indeed, were it not for the long shadow cast by Bush v. Gore, the 2000-2001 term of the U.S. Supreme Court might well be remembered for the unusually large number of cases in which "conservative" Justices voted for "liberal" outcomes and vice-versa."

Sirovich's article goes on to compare the current Supreme Court with the Warren Courts of the 1960s, and finds more similarities than have generally been supposed to exist. We do not go into the details of that, except to say that it is an example of something one needs a quantitative tool like SVD to be able to do.

The article has many other interesting statistics, some of which are listed below. Keep in mind that these are for the 70% (= 468) of all cases that the analysis can deal with.

While 47% (220) of cases were unanimous, the next most likely voting outcome, accounting for 10% (45) of all cases, was the 5-4 decision with Thomas, Scalia, Rehnquist, Kennedy and O'Connor forming the majority, as in Bush vs Gore 2000.
Of the 15% (72) cases involving a 5-4 majority, 45 had the conservative majority mentioned in the previous point, 18 had the Breyer-Ginsburg-O'Connor-Souter-Stevens majority and 9 had the Breyer-Ginsburg-Kennedy-Souter-Stevens majority. The swinginess value of O'Connor and Kennedy is obvious.
The most likely judges to agree are Scalia and Thomas (>93% of the time), followed by Ginsburg and Souter (>90% of the time).
Of the 33 cases where only one judge has dissented, Stevens has been the dissenter 21 times. Rehnquist, Scalia and Thomas have each been sole dissenter 3 times and Breyer, Ginsburg, Kennedy and O'Connor once each. Souter has never been the sole dissenter.
There are 2^(9-1)=256 possible voting patterns (where each person votes 'agrees with majority' or 'disagrees with majority'). However, only 12 of these account for over 80% (377) of all cases, and only 30 of them occurred more than once.

Sirovich got much of his data from http://supct.law.cornell.edu/supct/index.html and http://www.findlaw.com/casecode/supreme.html, and recommends The Oxford Guide to United States Supreme Court Decisions (Oxford Univ Press, 1999) and The Oxford Companion to the Supreme Court of the United States (OUP, 1992), both edited by Kermit Hall, as valuable guides for non-lawyers such as himself.

Searching for the WWW

2006-01-24T17:40:00.000-06:00

What happens when you search for "www" using different search engines?

Google sends you to Yahoo. [link] So does A9. [link]

MSN sends you to Slashdot, [link]

Yahoo sends you to the W3 Consortium [WWW Consortium] but when I tried it earlier four hours ago it sent me to hotmail.

LiveGraphics3d

2006-01-07T13:15:00.000-06:00

We've just heard (belatedly) about this really nice Java Applet called LiveGraphics3d that comes from the Mathematica-using math community. It seems relatively simple to use, is well documented, and while it has limitations, it could still be very useful for displaying things like cosmic ray showers, galaxy simulations, and results of machine learning algorithms. What's quite amazing is that you can define lines and surfaces using equations. It can handle at least a few thousand points quite well, too.

Martin Kraus, the creator, has some nice examples of impossible objects :

AIDS statistics

2005-12-27T23:54:00.000-06:00

IndexMundi also has some excellent drawing capabilities; for instance, the screenshot below shows the countries with the highest reported rates of AIDS... the top eight countries are in Southern Africa.

In a few cases, it's not clear if the basic numbers are correct - for instance, this graph shows Zimbabwe having 1.8 people living with AIDS - that's because Zimbabwe reports people dying of AIDS rather than living with AIDS.

Correlations

2005-12-27T23:39:00.000-06:00

Miguel Barrientos' IndexMundi allows you to plot correlations of several values... [IM Blog]

Migration and GDP per capita - slightly positive, indicating that wealthier countries have higher immigration rates (some interesting cause/effect arguments here)

Richer countries have lower infant mortality rates and have higher life expectancy and lower fertility and higher literacy and may not be getting richer(!) and lower unemployment and lower industrial production growth rate (!)

The Mystery of the Disappearing Teaspoons

2005-12-25T00:24:00.000-06:00

Megan Lim and other Melbourne researchers have produced a definite contender for a future IgNobel prize in the form of their five-month study on "the displacement of Camellia sinensis spathulatus" a.k.a. teaspoons. They report their results in a light-hearted holiday issue of the British Medical Journal.

They discreetly labeled 70 teaspoons, placed in tearooms around their institute (of 140 people) and observed, every week over five months, which ones were left. The result was that "56 (80%) of the 70 teaspoons disappeared during the study." Also, "the rate of loss was not influenced by the teaspoons' value" as shown in the picture below (which is from their research paper and which will probably get me into trouble with the journal for copyright breach).

Actually, looking at the graph above, expensive teaspoons did disappear more quickly initially, so we will clearly require further studies to verify their conclusion.

They go on further to note that "the half life of the teaspoons was 81 days" - that means that it takes about 2.5-3 months for half the teaspoons to disappear. However, this differs depending on how many people have access to the spoons - "The half life of teaspoons in communal tearooms (42 days) was significantly shorter than for those in rooms associated with particular research groups (77 days)."

The BMJ also allows people to respond to the study; one reader (Philip Colquitt) provides a good reason for why this kind of study is of great importance:

... if whole nations can be invaded by other nations, on the pretext of the existence of weapons of mass destruction[WMD], which WMD disappear without rational explanation, this suggests that primates(homo sapiens) may well be on the right track in trying to master spoon detection before going on to the more advanced stuff.

Articles about this. (Link to Google News)

The Perfect Paper Plane

2005-11-27T00:44:00.000-06:00

The Guardian reports on How to make the perfect paper plane - this Flash shows how to make the Leeds Avenger, the best designed plane at this week's British Flying Dead Trees Championships. Note that it got beaten by a simpler model called the Spruce Moose, as Martin Wainwright reports that :

"... In the best tradition of British inventions, this [the Avenger] repeatedly went into terminal nose dives in spite of complex flaps and tucks which had earned the judges' admiration..."

I also like the line describing other entries in the contest:

"...Other designers increasingly opted for desperately novel throwing techniques, last minute flap additions and in one case what looked like prayers...

The winning entry lasted 6.5 seconds before it met a well, but even otherwise it would have had trouble staying afloat the additional 20 seconds required to break the world record.

Counting Nobel Prizes

2005-10-12T09:14:00.000-05:00

Karen Kaplan of the LA Times writes in A Nobel Prize for Creativity about the differing ways that universities count Nobel Prizes.

"Renowned physicists Hans Bethe and Werner Heisenberg and economics guru Paul A. Samuelson are all counted among Chicago's Nobel brethren.

Wait a minute.

Didn't Bethe spend virtually his entire career at Cornell University? Isn't Samuelson considered the heart and soul of MIT economics? Did Heisenberg even spend more than a few months in Chicago?"

Hooray! I am a student at the University of Chicago, and ever since I saw Heisenberg's name on a "Nobel Prize" t-shirt I bought four years ago, I've been worried about the ridiculous way it counts Nobel Prizes.

Wolfgang Schoellhammer's 1997 survey counts prizes a lot better, and places Chicago at Number Five (instead of Two) on the list with 14 prizes (of which 8 are in Economics). MIT's probably long since overtaken it, which is a good thing. On the other hand, Harvard's got twice as many Nobels as MIT on this list, which seems rather ridiculous, even for 1997.

Words to in/exclude in application essays

2005-10-12T03:02:00.000-05:00

Karen Pine and others of the University of Hertfordshire Psychology Department have published a list of words to include and exclude from university admissions essays.

Best words: achievement, active, developed, evidence, experience, impact, individual, involved, planning, transferable skills

Worst words: always, awful, bad, fault, hate, mistake, never, nothing, panic, problems.

[Reported in Liz Ford's article Say the magic words in the Guardian.]

Penguin Poo Projection

2005-10-07T23:09:00.000-05:00

The Ig Nobel prize for Fluid Dynamics was awarded yesterday to Victor B. Meyer-Rochow and Jozsef Gal for their 2003 paper on Pressures produced when penguins pooh - calculations on avian defecation. This three page paper was published in the journal Polar Biology as a short note.

Picture from VBM-R & JG's penguin pooh paper

Suppose you have a penguin. Specifically, an Adelie or Chinstrap penguin. Penguins, like other higher vertebrates, do doo-doo. However, they are not turd-makers, i.e. don't drop shit. Instead, they shoot it about 40cm. (Why they do so is unclear - the authors suggest that this is to avoid "soil[ing] their plumage".)

Penguin shit is a semi-liquid/solid goo whose viscosity is -- by assumption of the authors -- about that of olive oil. You can think of viscosity as `resistance to flow' -- ketchup is far more viscous than water, for instance. If

penguin shit is like water i.e. not viscous,
a penguin's asshole is horizontal while firing (see picture above), and
the shitting is instantaneous (it actually takes about half a second)

then the pressure required to shoot it 40cm across the ground, from a height of 20cm, is around 34 mmHg or 4600 Pascals, about a third of human blood pressure.

The authors use the Instantaneous Shitting Assumption to avoid having to know the shape of the penguin's rear nozzle while firing. Having said that, they manage to cite a paper from 1883; they make use of the observation by one of the scientists on the Challenger Expedition that a penguin's cloaca (a fancy word for assholes in birds). It is normally a horizontal slit. But before you start thinking of how a possibly short-sighted cameraless 19th century ornithologist might determine this, bear in mind that they also cite a 1981 book chapter devoted to cloaca.

As mentioned earlier, fresh penguin guano is more viscous, i.e. flows less freely than, water. When this is taken into consideration, the pressure required is over twice as much. Under certain conditions it can even be as much as 60 000 Pascals.

The authors finally note that further trips to Antarctica are required to determine if penguins take into account wind direction while firing, as shitting into the wind would presumably be sub-optimal.

Rapid Serial Visual Presentation

2005-07-27T17:28:00.000-05:00

There's been some recent hype about RSVP, or Rapid Serial Visual Presentation, a technique introduced by K.L.Forster in 1970 (see the introduction here for a survey) with a bunch of Stanford researchers trying to make it a commercial product (BuddyBuzz) for delivering e-books to cellphones.

Mark Russell, Marilyn James, and Andrea Cohlmia, ran an experiment with twenty undergraduate students at Wichita State in 2001. [Link]. Regular reading was compared with RSVP at three different speeds - 250, 450 and 650 words per minute. Unsurprisingly, students preferred the regular method. However, reading comprehension of 250wpm-RSVP was almost the same as that of regular reading. Comprehension dropped with faster speeds, but that is unsurprising given the lack of experience of the subjects.

Experienced users claim to be able to handle 700 wpm.

If you want to play with this, try using GnomeRSVP or some other RSVP reader listed here by Matt Vance of MineZone.

Here's a horrifying thought - unless your are the budget director at the New York Times - you are surfing the web in 2008. All advertising banners now use RSVP. There are several banners on each page. People start paying online newspapers so they don't have to read banners.

Talking like Dead People

2005-07-19T13:10:00.000-05:00

Historical linguists and language evolution researchers have been working on how languages sounded like a long time ago. One method, pioneered by William Labov in the 1960s, is to just listen to old people talking, since people tend to keep pronounciations learnt in childhood.

Of course, that only works for languages several decades ago. If you want to know how a language sounded like centuries ago, a surprising source of information is songs where you know what word has to rhyme with what. Of course, just because you know a bunch of words sound the same doesn't mean you know what they sounded like. That requires additional information, such as pronunciations from slow-changing dialects (e.g. of more isolated communities).

David Crystal has been teaching actors at the Globe how to pronounce Shakespearean English. The BBC has a good report on this:

They say their accents are somewhere between Australian, Cornish, Irish and Scottish, with a dash of Yorkshire - yet bizarrely, completely intelligible if you happen to come from North Carolina.

Somehow, North Carolina doesn't sound like an isolated linguistic community. That must be a coincidence.

Cycling

2004-07-14T04:12:00.000-05:00

The effect of wind speed on cycles has been analyzed.

Landmine hunters

2004-05-18T13:42:00.000-05:00

Landmine detection is a huge problem. Animals are often used to hunt down mines, such as dogs & dolphins. And other exotic fauna (and flora!)

Caffeine

2004-05-12T02:57:00.000-05:00

Caffeine is now good for you, if you drink it regularly. Somehow, I don't think my mum will agree with this research.

Meanwhile, there are suggestions that caffeine should be banned for athletes for ergogenic reasons, whatever that means. Banned for three days before competition, that is.

There seem to be several VRML models of caffeine molecules: 1, 2, 3, 4. Or maybe they are all the same copy floating around.

Here's an interesting tutorial about testing for caffeine in horse doping. Presumably giving your horse M&M's before a race does not count as doping.

US losing its domination in science?

2004-05-11T20:06:00.000-05:00

Well, well! The United States is reportedly losing its domination in science. That can only be a good thing, as it will force us in America to look abroad more often. The tendency towards insularism over here is high. But how much domination are we talking about here?

One possible (as dodgy as anything else) benchmark is
Nobel Prize counts, which results in a ranking of top universities as Harvard, Cambridge U, Max Planck (Munich), U London, Chicago, CalTech, MIT, Stanford, Berkeley. That's for all science (including Economics) fields combined. For individual fields, partial rankings are available for physics, chemistry, medicine, and economics. The site reads "The 481 Nobel prize laureates came from institutions in 24 countries. 45.7 % of these institutions are in the United States, 15.2 % in Great Britain and 12.7 % in Germany."

If the projection is (and I'm pulling numbers out of a hat here) that by 2020 'only' 30% of Nobel institutions will be in the United States, I'm all for it. Keeps us on our toes, and prevents our military and traders from throwing their weight around so much.

As a caveat, note that there are other University rankings.