NORKS, a few words on education, and more on Correlation and Causation

View 765 Tuesday, March 05, 2013

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Sometimes I remember the strangest things. More than fifty years ago there was a Western radio drama, Gunsmoke, starring William Conrad as Matt Dillon and Parley Bear as Chester. In one of the episodes young would-be gunfighter came to town. He announced that he was going to kill Matt Dillon in a fair fight so as to gain his reputation and make a lot of money hiring out in a range war. Dillon didn’t take him seriously, but the kid kept insisting, and finally as Dillon was coming out of the Longbranch he shouted some threat. There was gunfire. Dillon said “Sorry kid, this time I believed you.”

Norks threaten to repudiate Korean War ceasefire on 11 Mar 2013, shut down hotline at Panmunjom.

<http://apnews.myway.com/article/20130305/DA4QTUEG2.html>

Roland Dobbins

North Korea is a major threat because of the massed artillery along the border. The location of most of the guns is well known and plotted by both US and South Korean gunners and pilots.

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Carpenter Avenue School, the local public school in Studio City, is well known as an exceptionally good school, and was even before it became a charter school. Given the general level of competence of schools in the Los Angeles Unified School District, Carpenter certainly is exceptional, although we didn’t think it sufficiently so for our kids even though it’s only two blocks away. We sent our boys to St. Francis, but that’s another story.

The big story is that parents are gaming the system to get their children into Carpenter, falsifying their addresses so as to appear to be in the school’s district, and thus flooding the system so that people who do live in Studio City can’t get their kids in the school. The local talk radio hosts are making much of this and debating whether the parents doing this should be ashamed of themselves.

Given that the entire LA Unified School District is a fraud, taking between $7 and $8 thousand dollars per student and achieving a dropout rate greater than 40% and an illiteracy rate approaching 50%; that LAUSD permitted a teacher caught on video feeding his pupils cookies frosted with his own semen to retire rather than be fired and continues to pay his pension as he awaits trial in jail, that in ten years LAUSD has fired fewer than 50 teachers for incompetence, and is generally awful, one could make the case that the school system is a fraud, a giant con game, and questioning the ethics of those who chose to con the con men is a joke.

Of course Los Angeles isn’t alone here. The 1983 National Commission on Education concluded that “If a foreign government had imposed this system of education on the United States, we would rightly deem it an act of war.” The national school system hasn’t improved since that time. Most state budgets spend more on education than on anything else, and with a few exceptions it’s all pretty well fraudulent. If someone offered you $750,000 a year to educate 100 students, do you think you could manage to do that? Most of us certainly could, providing each student with a fully loaded iPad in the bargain. But of course that’s idle speculation. We aren’t going to reform the school system. The only chance your kids have is for you to game the system, or avoid it altogether.

Begin by making sure they can read before the go to school. By read I mean be able to read nonsense words. Any kid who can read can read “’Twas brillig and the slithy toves did gyre and gimbel in the wabe, all mimsy were the borogroves, and the mome raths outgrabe.” Not many five or six year olds will have the foggiest notion of what the means unless you have been reading to them from Alice (or they have been reading it themselves: six year old kids can in fact read Alice, but be prepared for a lot of pesky questions about what’s going on). Any kid (of any age) who can’t read that sentence can’t read. They may be “reading at grade level” but that usually does not mean they can read. If you can read English you can read long words you do not understand (or which cannot be understood, such as deamy and precognosis). Those who can’t read those words can’t read English, and you might be astonished at how many twelve year old children can’t read them.

Many studies have shown that if you can’t read by the beginning of fourth grade, you are not likely to have any career in the technical subjects; you’ll just get too far behind before you get into high school. I suppose that is disputable – surely one can find examples for whom it was not true – but it’s true enough, given that the remedy is simple. For generations English upper and middle class children were taught to read at age 4 by nannies or their parents, and most English public schools expected the kids to be able to read when they arrived. I don’t think those kids were particularly better protoplasm than ours. But I’ve said this often enough before. If you want to know more, http://www.jerrypournelle.com/OldReading.html.

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Our small discussion of correlation and causation yesterday impelled Mike Flynn, who thinks a lot about this sort of thing – he’s a quality control expert, which means he is very much concerned with advanced studies in statistical inference – to write a short essay. It may tell you more about causation and correlation than you really wanted to know, but those who actually have to deal with such matters ought to know this sort of thing at this level:

The Causes of Correlation

Regarding recent comments on correlation and causation, a few observations:

1. If X causes Y, then X and Y will be correlated IF a wide enough range of X is examined. Otherwise, it is possible for X and Y to appear uncorrelated.

2. If Y causes X, there will likewise be a correlation, if a wide enough range of Y is examined; but researchers may be fooled into supposing that it is X that causes Y.

Example: in the famous case of the Storks of Oldenburg, an excellent correlation obtained between the population of Oldenburg, Germany, during the 1930s and the number of storks observed each year. Do storks bring babies? No, babies bring storks: as the town grew, more houses were built, resulting in more chimneys, and the European stork likes to build its nest in chimneys. So, more nesting places.

3. If Z causes both X and Y, there will be a correlation between X and Y even though there is no causal connection whatsoever.

Example: in a chemical reaction low process yields (Y) was correlated with high pressure in the vessel (X). The suggestion to increase yields by lowering the pressure was met with scorn because: there was an impurity in the raw material (Z) that interfered with the reaction and lowered yields AND also caused frothing in the vessel. The standard operation procedure instructed the operator to combat frothing by increasing the pressure to hold down the foam. So low yields and high pressure were associated, but manipulating one would not change the other. Both were effects, not causes in this context.

4. If X and Y are both on a trend or cycle during the same time period, the respective time series will correlate even if there is no causal connection.

Examples:

* Columbia river salmon runs go up and down in roughly eleven year cycles. So do sunspots on the sun. Do sunspots cause salmon? Do salmon cause sunspots? Is there a lurking Z that makes salmon eager to spawn AND causes the sun to boil?

* An example I used to use in training classes. The % of women participating in the labor force (X) has been increasing smoothly since the 1880s. The % of foreign cars sold domestically (Y) was increasing from 1955 to 1990. The correlation between X and Y was in the high 90% range. Does this mean that we can save Detroit by getting women back in the kitchens? Or only that two trends will always correlate?

* If global temperatures are increasing and atmospheric CO2 is increasing during the same time frame, they will correlate.

5. Coincidence. There was a longstanding correlation between the size of the universe and the size of my suits. Space was expanding, and so was I. But if I lost weight, would the universe begin to contract? Hemlines and stock prices is another classic example.

Example: Science Can Tell If You’re A Racist Just By Looking At You http://wmbriggs.com/blog/?p=7407

6. The Unabomber Effect in Multiple Correlation. When the Unabomber taught math at Berkeley he said that given seven independent variables (X1,…, X7) you can fit any finite set of data (Y). It’s only a matter of finding the right coefficients. (It might not survive new data; but then you simply re-analyze and come up with a new set of coefficients and, presto, you get another fit.) This could become an enormous problem with Big Data and automated data mining and adjustment.

Actually it is already an enormous problem with Big Data and automated data mining. But you know that. Statistical dragnets can find a lot of interesting correlations. Treat them like hypotheses to be tested and you may learn something. And every now and then an unexpected correlation does lead to some real discoveries, which is why keeping careful case histories is so important to medicine.

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