Archive for August, 2006

Too much water in my name, part 3: too much acid in my water

Since we’re on the subject of water (again), had yet another fun experience. Earlier this week, K noticed a couple of inches of water in the pan under our hot water heater. Yep, it seems to be leaking. This is the water heater that I installed one year ago. It was a replacement for a water heater installed 4 years before by the previous owner.

The tendency of our appliances to rust, particularly the water heaters led me to test the pH. Ideally, it should be between 7.0 and 8.0 (or just neutral to slightly basic). Ours was around 5.5 or somewhat acidic. This is a reasonably common problem for people with well water and it causes all of the symptoms we’ve seen (including the degredation of all brass plumbing fittings).

Fortunately, they make a “pH neutralizer” which is really just a fancy name for a tank filled with calcium carbonate (which is just a fancy name for chalk) that water flows through. I’ve got one on order, it should be here tomorrow. Once I get it installed, I’ll see if I can get the store to honor the warranty on our current water heater and replace that too.

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Too much water in my name – part deux

We had a batch of thunder showers come through last night. We got about 2, maybe 3, inches here. Sometime during the evening, K and I ask each other, “what’s that noise?” Turns out we had a leak in the roof that was dripping down (and through) the second story wall, onto one of the logs making up the first story and into the breakfast room. From there it was splashing onto the door to the deck and making the noise we heard.

All of which led me to climb the 45 degree pitch of a wet/slippery roof this morning, right before heading into a meeting at the office, with a tube of roofing caulk, patching up a couple of cracked shingles. We’re getting more rain now – we’ll see how well this holds.

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Dropping SAT Scores

Matt Yglesias sees the recent Washington Post article describing the fall in SAT scores after the most recent test changes and asks what’s the big deal. On the face of it, Matt makes some good points. Scores are only down 7 points (5 in reading and 2 in math) and for any given student, that really isn’t a big deal. The Washington Post article, while suggesting that there may be some underlying causes (e.g. the test changes or students not learning enough) also notes that it could be a one year blip.

I did a quick look at some of the data for the SAT. It turns out that in 2005, the mean reading score was 508 (N=1,475,623 SD=113). In 2006, it was 503 (N=1,465,744 SD=113). For math in 2005, we have a mean of 520 (N=1475623 SD=115) and in 2006, mean of 518 (SD = 115 N=1465744).

Armed with this information, and the reasonable assumption that the data are normal, we can compute the likelihood that the difference between these two years is due to random sampling of students. Let’s do a student’s t-test. For reading, we get a t-value of 37.94; for math, 14.91. The probability that the reading scores could happen by chance is 0, as in less than the epsilon of my stats package (R). For math, it’s on the order of 10^-50.

Given that, we know that there is a difference here. It’s not a statistical blip. If we look further at the data, we see that SATs are remarkably consistent as long as the test isn’t changed. Essentially, we are dealing with such a huge number of students (1.5 million per year) that blips don’t show up. So that leaves us with two possibilities:

  1. graduating seniors have gotten dumber over the past year; or
  2. the change in the test is significant

I can’t definitively disprove hypothesis 1, but given the large number of students and the general SAT consistency, I think that it is not likely to be the issue. That leaves us with hypothesis 2 – the change in the test is likely to be significant. I don’t see a way to avoid saying this is the case.

Of course, on a per student basis, the change isn’t that large, but it is real and not a statistical artifact; and it means that you can’t compare SATs for students from 2005 to students from 2006.

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“Real wages fail to match a rise in productivity”

An article today in the New York Times titled “Real Wages Fail to Match a Rise in Productivity” takes a look at how wages have risen, or more to the point failed to rise, during the most recent economic expansion.  At a time when productivity (the monetary value of an hour of labor) has risen dramatically, increasing corporate profits, employee wages are basically falling.  If you include benefits such as health insurance, they are rising – but nowhere near as fast as productivity.

The most compelling paragraph in my opinion:

Average family income, adjusted for inflation, has continued to advance at a good clip, a fact Mr. Bush has cited when speaking about the economy. But these gains are a result mainly of increases at the top of the income spectrum that pull up the overall numbers. Even for workers at the 90th percentile of earners — making about $80,000 a year — inflation has outpaced their pay increases over the last three years, according to the Labor Department.

Think about it.  If the average wage is rising, but the wages for the bottom 90+% of workers are decreasing, then that top earners are doing quite well for themselves.  But even looking at the 90th percentile doesn’t fully explain what’s going on.  Wage increases are similarly skewed within the top 10% with the top 1% having dramatically higher wage increases than do the 90th to 99th percentiles.

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It’s official – the government *does* consider evolutionary biology to be a science

Last week there was a minor uproar in the academic world when the government presented the list of majors that qualified for money under the National Science and Mathematics Access to Retain Talent (SMART) Grant program. The problem was that evolutionary biology was left off of the list. The feds claim that this was an oversight and on Friday added evolutionary biology back to the list of qualifying majors.

So, even I am not so paranoid as to think that this was a conspiracy to keep students from studying evolution. But at the same time, I am not so dumb as to think this was accidental. The list of majors comes straight from the Classification of Instructional Programs codes. In the biology section, there are ten biology related programs. Of those ten, only one was missing – evolutionary biology.

Like I said, I don’t think it was conspiracy. Instead, I suspect that a low to mid ranked staffer assembling the list thought that s/he would make the boss happy by leaving off that nasty “e” word.

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The social life of the a Duke undergraduate (as seen in the press)

The Dallas Morning News recently published an editorial by Thomas Hibbs entitled “College Kids Get Brain, No Soul.” In the editorial, Hibbs references the exceedingly disturbing article in Rolling Stone called “Sex & Scandal at Duke.

The Rolling Stone article discusses the social scene at Duke where “work hard, play hard” has always been a motto. According to the article, in recent years, the “work hard” portion has morphed into an obsessive desire to please faculty, working to produce high quality papers which will be accepted by professors in order to get good grades, graduate with honors and get a good job. The “play hard” portion of the motto has turned into an obsession with alcohol and casual sex, bleeding back into “working hard” to maintain the perfect body, social connections, etc.

Hibbs read the article and concludes that Duke (like other prestigious universities) is not doing its job in teaching students. That it teaches the mind, but not the soul and that this failing leads to the behavior describe by Rolling Stone. He concludes by saying that parents and students should be more selective in choosing schools and professors, selecting those that feed the soul as well as the mind. I am sure that his role as dean of the Honors College at Baylor is entirely coincidental.

Beyond the, admittedly minor, conflict of interest, Hibbs commits a logical fallacy by confusing cause and effect. He implies that Duke and other prestigious universities are failing students by either allowing or encouraging them to ignore their spiritual/emotional health. My personal belief is that the students who exhibit the behaviors described in the article are more likely to attend a school like Duke. I believe that these behaviors are characteristic of “generation Y” and that Duke and similar schools attract the cream of the crop of students (i.e., the most successful) who are most likely to exhibit the traits of their generation.

That’s a big claim to make without providing a bit of elaboration, so what exactly do I mean? The first thing to note is that the Rolling Stone article draws a very sweeping picture of Duke students, but in places notes that it is being descriptive of the “Top 500” or the most popular subset of the undergraduates out of a population of 6,500. I’ve known several Duke undergraduates and the article does not describe them at all. Instead, this is “the beautiful people.”

As the RS article makes clear, a driving factor in the students’ behavior is a desire for acceptance or approval. From what I’ve seen, this desire for acceptance is particularly strong in gen-Y. They desire to be accepted by peers (as do all teenagers), but they also seek acceptance by parents and teachers. This drive for parental and teacher acceptance easily turn into academic success, at least at the high school level. You regurgitate material, you don’t need to think for yourself about it, and you make your parents and teachers happy.

Students whom are strongly motivated by this type of acceptance are likely to perform best in schools. They may be likely to participate in many extracuricular activities (acceptance by peers and society) and are likely to study hard to ace their SATs (again to please their parents). All of this means that the student motivated by acceptance is more likely to get into a prestigious university. Once they get into the university environment, they find that the quest for acceptance leads to engaging in different behaviors of the kind described by Rolling Stone.

There may be things that universities can do to curb such destructive behavior, but my belief is that the root causes start at home, well before the students go to college.

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Update on the Ohio University plagiarism

In reference to my previous comments on the plagiarism scandal in the school of engineering at Ohio Universtity, yesterday the university announced a set of “comprehensive strategies to address academic honesty.” Among the steps being taken is to examine 55 theses for signs of plagiarism. From these, they have found 35 incidents that will require a hearing. Punishments handed out could include the revocation of the former student’s degree. Furthermore, the two professors whom have been implicated have been relieved of their advising duties.

This is actually quite amazing. Now, from what I’ve read of the case, Ohio University was more or less forced into these actions. But it is still surprising to see a university take these kinds of steps. Now, I still suspect that this was largely the result of not understanding american academic cultural norms and was not intended as cheating. However, it is good to see some accountability, particularly for faculty members who should have known better.

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“The Body Hunters” by Sonia Shah

shah.jpgThere’s nothing I love more than a good book, unless it’s a free good book. Last week I was sent “The Body Hunters” by Sonia Shah. I’ve been sent free books based on my job before (either as a research professor or as security officer), but I’ve never been sent a book on the ethics of the pharmacutical industry before. It took me a bit to figure out, then I realized that I’m presenting at a Human Subjects conference. I’m sure they sent the book to all of the presenters.

Anyway, I read the book over the weekend and it’s very interesting. Shah takes a close look at the history of drug development and the factors which have let to US companies outsourcing the majority of clinical trials overseas to poor countries. The basic ethical problem comes about from two factors. First, the majority of new drugs are copy-cats trying to cash in on the drug market. They do not attack problems in new ways, they simply attack a problem in a way that’s similar to other drugs currently on the market. For example, all of the proton pump inhibitors for preventing heartburn. Once you know to shut down the acid pumps in the stomach, one way is as good as another. This is also true for anti-AIDS drugs, various anti-parasitics, etc.

The second factor is that statistically demonstrating a new drug is effective is easier in a placebo trial – a trial where the control is no treatment at all. You can still demonstrate effectiveness when the control is active, however, it requires a larger trial that takes more time, money and volunteers.

The ethical problem is that once a safe and effective treatment is known, a doctor has a moral obligation under the 1975 Declaration of Helsinki to ensure that a patient in a clinical trial is receiving that treatment. Moreover, in the U.S., which is by far the biggest drug consumer, patients won’t sign up for a placebo trial once there is a known, effective treatment.

To address the practical problem of not having enough test subjects, clinical trials are increasingly conducted in poor countries where patients often have no choice and grasp at any straw to possibly receive treatment. Shah also provides evidence that the lack of a regulatory structure in many of these countries leads to researchers ignoring the idea of informed consent and lying to get test subjects.

Shah argues that the best way to resolve the ethical problem is to require researchers to prove that their new drug out performs the best available treatments. This would involve testing not against a placebo, but against other, known effective, drugs. It may require larger trials, but it is definitely more ethical.

In addition to addressing the ethical issues, Shah presents a very disturbing look at the financial side of the drug industry. I need to talk to a few friends in the medical industry (one runs medical trials, the other is a phd/md focusing on oncology) to get their impressions, but at the very least I can recommend that folks read the book – it’s a well documented and clearly presented examination of an industry that many of us depend on.

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carrier thermidistat design – let’s put it in the category of needs to be fixed

Back when I was a grad student and just about to finish up, the school of engineering turned a class of 60 freshman over to me to teach intro to numerical methods for engineers. I tried to liven things up by emailing the occassional engineering funny to my students who even reciprocated. The following is a brief excerpt from an engineer identification test that was sent to me by a student.

To the engineer, all matter in the universe can be placed into
one of two categories: (1) things that need to be fixed, and (2)
things that will need to be fixed after you’ve had a few
minutes to play with them. Engineers like to solve problems.
If there are no problems handily available, they will create
their own problems. Normal people don’t understand this concept;
they believe that if it ain’t broke, don’t fix it. Engineers
believe that if it ain’t broke, it doesn’t have enough features
yet.

That brings me to an issue I’ve been having. A couple of years ago, we put in a new heatpump with humidifier, it came with a new thermidistat which didn’t seem to work too well. When the A/C cut on, the temperature on the thermostat rose several degrees, at one point jumping from 78 to 86, while the temperature in the area remained constant. I realized that the problem was the relays. The A/C kicks on, the relays heat up and the thermister gets hot. We called the installer, got a new thermidistat. It did the same thing.

We discovered that we could use a small fan to blow air on the thermidistat. That worked well, but was irritating. So we moved the thermostat to a place with more airflow. Same problem, but to a lesser degree – the A/C cuts on and the system jumps from 78 to 79. Of course, to get it back down to where it would shut off, the thermostat ran the A/C until the house had cooled to about 75. Bah.

Finally, this weekend, I opened up the thermostat and added some redneck engineering to it. I insulated the relays using cotton balls and tape. So far so good. If this didn’t work, the next step was to just buy a different model of thermidistat. But let’s face it, do-it-yourself insulation is more fun. So, for the record, we can officially put the design of the carrier thermidistat in the category of things that need to be fixed.

UPDATE: let’s spell carrier correctly, shall we? 

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racial profiling for terrorism

I’ve heard and read a number of people saying “political correctness be damned, we should use racial profiling to identify terrorists.” The problem I’ve always had with this is that it makes no sense. Try the following test, identify the terrorist:

  1. young muslim male
  2. young muslim female
  3. asian male or female
  4. caucasian male or female
  5. black male or female
  6. hispanic male or female

If you said that 1 and 2 have been terrorists and therefore we should profile them, you are partially right. However, what about all of the asian terrorists (e.g. Fillipinos)? Caucasians? Hmm, the IRA, David Koresh, Timmothy McVeigh, etc. As near as I can guess, the only racial groups that shouldn’t be profiled would be blacks and hispanics. This can’t work.

NBC Nightly News just had an interesting story on behavioral profiling being done at the airport in Orlando. Essentially, the police have been trained to look for suspicious behaviors, not suspicious racial characteristics. This is a much sane approach from the security perspective and can be much more effective with a lower rate of false positives.

POSTSCRIPT: from the security standpoint, any action needs to be considered from the risk mitigation standpoint. What’s the risk? What is the rate of false positives (FP) of the action? What are the costs of the FP? What is the rate of false negatives (FN)? Costs of the FN? etc, etc. Racial profiling fails under a risk mitigation analysis. Behavioral profiling may make sense.

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