Friday, April 27, 2007

Keep on Studying

I never studied until I got to college. I always got by just fine by paying attention in class and doing my homework. I didn't start taking notes in earnest until college. But even in college, I didn't need to study much. It wasn't until graduate school that things got too hard for me to just absorb and I actually started studying on a regular basis.

As a consequence, I had no study skills. Notecards? The first time I ever made them, I was a sophomore taking organic chemistry. Even then, my "studying" consisted of making the notecards, and maybe going through them a couple of times in the days leading up to the exams. Reading the textbook? I never really tried that until my senior year of college. Of course I would read the books in my literature courses, and my social science textbooks, but I never read a science textbook until I took numerical linear algebra my final year of college. It helped, believe it or not! There was actually information in that book, explained in a slightly different manner than my professor had explained it in class, and that made a difference in my learning. But still, I didn't really study; I just read it once and that was enough to get an A in the class.

In graduate school, I actually had to do more than just pay attention and take notes in class, do the homework, and read the textbook once. I had to read the textbook and take notes. I had no idea how to take notes! So I would copy word-for-word from the textbook at times. In particular, I remember I had a really tough time in my operating systems class. Looking back, I realize that the course was little more than a bunch of definitions and new vocabulary words. If I had only had the study skills, I could have done a lot better in that class.

In my more math-oriented classes, I would work out the examples in a notebook, going through the steps they skipped in the book. This was actually good training for reading math papers.

The summer of my first year of graduate school, I began to study for the qualifying exam. This was a 90-minute oral exam, covering a broad syllabus of numerical analysis. There was a textbook that was a perfect study guide for the exam, so I worked with two other students who were also scheduled to take the qual that fall, and we went through the entire book, one chapter per week. I'm so glad that I had others to study with, because I suspect that I would have lacked the self-discipline to work through the book. We did all the exercises at the end of each chapter, and we gave each other mock quals. My advisor also gave us mock quals.

I had never studied so hard in my life! But by the end I was getting pretty burned out. So I was really devastated when I failed the exam. And I was angry, really really angry! Something extremely unfair had happened during my exam: one of the professors behaved inappropriately, but despite this fact, they counted the exam against me. I was terrified that this exam showed that even with all that studying, I was too stupid to continue in the graduate program. But I retook the exam in the spring, and I passed, despite my bad attitude. I was very hostile during the second exam. Later on, I became on more friendly terms with one of my examiners, and I asked him if they'd passed me just because they thought I might go ballistic otherwise. He laughed and agreed that I had been hostile, but reassured me that I had passed on my own merits.

After all my exams and coursework was over, I thought that surely this would be the end of studying. Alas, it was not. I had to read and understand the scientific literature in my field, and that required studying papers. It is hard to read papers, because they are terse and boring, and my attention span is short. It takes several readings to understand even the simplest paper. First I skim the paper through, to get a feel for the big idea of the paper and the important conclusions. Then, before my hand started causing me so much trouble, I would take a lot of notes and work out all the equations on the second pass. Even now, I splurge and work out all the equations by hand, but I do most of the note-taking on the computer. Unfortunately there's no easy way to write equations on a computer, so I get bogged down in the notation if I try to do it on the computer. Then I'll read it a third time through just to make sure that I didn't miss anything.

And I have to study a lot anytime I learn something new. For my job, I had to learn C++ templates, something I didn't really know that much about. So I found some good tutorials on the internet, and worked through them.

Back when I was in high school and early in my college career, there wasn't really very much on the internet. Today, however, you can find almost everything you would ever need to know on a computer. So another study skill I've had to develop is the web search. I use Google to find a lot of solutions to problems that I encounter while programming: strange messages from the compiler, object-oriented programming concepts that I don't understand, etc. I also use CiteSeer to look for math and computer science papers on topics related to my research, such as optimization, multiwavelets and load balancing.

Even though I'm out of school, and have been for nearly two years, I still use study skills almost every day. I guess that learning new things is why this job remains interesting. Keep on studying!

Thursday, April 26, 2007

Must Reads on Abortion

In light of the recent Supreme court decision on partial-birth abortion, here are some interesting takes on the issue.

First, my better half (a.k.a. Captain Fatbody) argues that if you're against abortion, you should be opposed to the death penalty too.

Next, a man faces an ethical dilemma he never thought he'd have to, when his pregnant wife loses consciousness. And a woman explains why she had a partial-birth abortion.

These last two articles do a good job of explaining why the abortion decision should be left to a woman and her doctor (or, in the case she's incapacitated, her designee). In both cases, the baby was very much wanted. There was just no way that it would have been viable.

Monday, April 23, 2007

Old McShrieker

Old McShrieker had a scream,
Aah aah aah aah ahh!!!!
And when he squealed it pierced my ears,
Aah aah aah aah ahh!!!!
With a screech-screech here, and a squawk-squawk there,
here a screech, there a squawk, everywhere a screech-screech!
Old McShrieker's lungs work well,
Aah aah aah aah ahh!!!!

Saturday, April 21, 2007

Math and Patterns

I mentioned earlier in the week that math is all about patterns, and that as humans we are naturally good at pattern matching. It's true that we're good at pattern matching. It is an excellent tool for survival. In the past, the person who was able to spot the predator behind the bushes first (i.e. compile the image of the predator from the bits and pieces in the field of vision) didn't get eaten. Even today, it comes in handy by helping us avoid danger.

Our pattern matching skills are really amazing. We can recognize a person from a tiny, two-dimensional blob of color known as a photograph. We can slap the right place when we hear a sound we recognize as a mosquito landing on the arm. We can open the fridge and know that something is rotten thanks to a scent we recognize as "week-old chicken."

And even more amazingly, this pattern recognition can trigger memories of our experiences. If the government investigator asks us about a high school classmate, we may not immediately recognize the name, but upon seeing a yearbook photo, all the memories come rushing back. The sound of a certain breed of dog barking could be enough to spook someone who was once bitten by a dog. The scent of a certain cologne may remind someone of her ex-boyfriend, and depending on the nature of that relationship, may induce feelings of nostalgia or of fear.

Our pattern matching skills are so fine-tuned that we sometimes find patterns in cases where there really are none. Man-in-the-moon, anyone? How about inkblot tests? How about hitting streaks in baseball? We are made to look for patterns, and we find them in the most unlikely places. Because of the clustering illusion, if something doesn't fit our expectations of what randomness looks like, we assign it a significance it does not deserve.

Mathematicians look for patterns, but good mathematicians look for ways to invalidate the patterns they find. The work I do with algorithms is all about finding patterns and making sure that they are really patterns.

How does a person design an algorithm? Here's what I do:

1. Do a simple case of the thing for which you're trying to find an algorithm. Look for pieces of it that can be broken down into individual steps. Look for paths of dependence (e.g. I have to do X before I can do Y).

2. Try your algorithm on a more complicated case. Look for errors and inconsistencies, and alter your algorithm accordingly.

3. Pretend that you know absolutely nothing and have no preconceived notions beyond the consistency of the basic laws of physics and arithmetic (i.e. pretend you are a computer). Follow the algorithm literally. Does it work? If not, refine the algorithm using steps 1 and 2. If so, try it on a few more cases. If it still works, you probably have a good algorithm.

I love patterns. But, I love them so much that it's important to me that the patterns I see are valid patterns, rather than statistically probable outcomes to which I artificially assign meaning.

For example, there is no significant meaning to coincidences that don't feel coincidental, tarot card readings, or psychics. Greta Christina explains it well but I will summarize and then augment her argument a bit. Basically, the likelihood of any single outcome at one moment in time is very low. But, the aggregate probability of one of multiple unlikely outcomes occurring over the course of time is fairly significant.

Let me explain with an example. There is a 1/365 chance that anyone I meet will share a birthday with me (ignoring leap year). Yet if I'm in a room with 22 other people, the chance that two of us share a birthday exceeds 50%, and if I'm one of 57 people, the chance grows to more than 99%. How can this be?

This is because the so-called birthday paradox takes the aggregate probabilities of any one person's birthday matching another's and adds them all together. So yes, it is unlikely that one of these other 56 people shares my birthday, but it is quite likely that a pair with the same birthday exists.

Putting this into a real-life perspective, it's unlikely that tomorrow morning at 7:13 a.m. EDT, a person I know will die in a plane crash. However, it's much more likely that over the course of my lifetime, someone I know will die in a plane crash. This is because a) I meet more people as life goes on, and b) more and more plane crashes occur as time marches on (not necessarily more frequently, I'm just saying that they keep happening and each one makes it more likely that I'll know a victim).

Understanding how to distinguish between true patterns and the clustering illusion is certainly important beyond just work as a mathematician. It will make you resistant to false claims by psychics, snake-oil salesmen, and even your own mind.

Thursday, April 19, 2007

Fat Acceptance and Weight Loss

I came across the following video about fat acceptance on Greta Christina's blog. I agree wholeheartedly: fat is a three-letter descriptor, not a dirty word.

I thought that the woman in the video is quite beautiful, really. Some people, like her, just have a certain radiance about them that makes them beautiful, independent of weight. There are plenty of attractive people of either sex across the spectrum of weight.

My longtime readers know that I lost 68 lbs over the course of twenty months from 2003-2005, with the help of Weight Watchers. I think Weight Watchers is a great program, because it teaches you more than just healthy eating. They incorporate behavioral changes into the program, making it a lifestyle change more than a diet. And these behavioral changes affect more than just your eating habits: they end up permeating your life and help you to make wiser choices in everything, more than just what you put in your mouth.

I'm back in Weight Watchers again, because thanks to pregnancy, I gained everything I had previously lost and more. Since mid-December, I've lost nearly 15 lbs (and since the day before Vinny's birth, roughly 35 lbs total). It has been much slower going this time. But I know that I have a proven track record of weight loss, and I can do it.

In both cases, I didn't decide to lose weight so that others would like me better. I lost weight for my own sake. I had a number of personal reasons, including for the sake of my poor, very weak knees. They were positively creaking in the days leading up to Vinny's birth. They thank me profusely for getting some of the load off them, and as I continue to get lighter they will be even more grateful.

I'll never be skinny. My goal weight is at the very top of the healthy range. Even when I was at that weight before, I was still quite curvaceous and I had a few rolls. I am sure that I could become a stick on legs but I have no desire to do so.

I'm never going to be fashion model material but I am actually glad of that. Fashion ideals distract women from healthier pursuits that would build upon their actual assets. Instead women end up chasing after the elusive ideal look, a look that for most women is unhealthy and untenable. If I were a fashion model, I would need to be one hundred pounds lighter. That's nearly half my weight I would need to lose!

The fashion industry can bite my big behind. Real women have curves and I certainly have no desire to support purveyors of the myth that they don't (such as the trendy stores that the woman in the above video visits).

I put on my excess weight in my twenties, while in graduate school. Growing up, I was never skinny, but I didn't get overweight until then. So I've lived on both sides of the fence. When I was younger, I was probably more judgmental of overweight people than I am now. My outlook has always been the same, but experience as an overweight person has deepened my understanding. I've gone from an academic appreciation to a personal recognition of the truth about fat. I talked more extensively about it in an earlier blog entry.

Being fat is not a character flaw! A person's weight is influenced by many variables, including genetics, personal habits, and priorities. The best way to make sure that you're thin is to have two thin parents, and preferably, four thin grandparents. (I had two thin parents but only three thin grandparents. My sisters don't have the same tendencies to gain weight that I do, nor do most of my cousins, although I am not the only heavy one.)

The reason that I have lost weight in the past and maintained it (except for pregnancy) and am losing weight currently is because I have made it a priority in my life. I have decided that it is important to me to lose weight and keep it off. If at some point my priorities change, then I might gain the weight back. In the meantime, I plan to go back down to my pre-pregnancy weight and stay there.

Sadness for Virginia Tech

I am still stunned by the news of Monday's horrible shooting massacre over at Virginia Tech. I've never been to Blacksburg, although I know a few alumni and I know a couple of faculty over there too. But I don't need any tangible connection to feel so sad for all the people whose lives were so devastated by the work of that gunman.

As a mother, I can't imagine learning that my child died so suddenly, or even worse, that my child was the one who had perpetrated all those deaths. As a daughter, I can't imagine the devastation that the children of murdered mothers or fathers must be feeling right now. As a person experienced with mental illness, I can only guess how the gunman must have felt to drive him to commit such a horrible act. I wonder what would have helped him.

I feel very sad for all those whose lives will never be the same.

Monday, April 16, 2007

Even More Migraines

I had another migraine at work today, but I had left the pills the doctor had given me at at home, so I couldn't take them. I consoled myself with the thought that it probably wouldn't have helped anyway.

Good at Math?

Yes, you are. As my blogfriend Tony points out in his excellent article, "Who Can Blame Them," math is the science of pattern recognition, which all of us excel at. It's the (inconsistent) notation and the rote memorization that turn people off to math, the most natural of sciences. Go read his blog entry (and heck, his whole blog while you're at it)! It's really good!

Sunday, April 15, 2007

Weather Update

Last weekend, Dad and Marvis came back through here on their way home from spring break. They arrived late Saturday evening and left late Sunday morning. They were of course excited to see their grandson. But almost as exciting as that is what Dad saw outside as I was making pancakes for breakfast on Sunday morning.

We've had quite a cold snap over the past couple of weeks. We are well into spring so this has been very hard on all the plants. Before the cold snap the dogwoods were at their peak and we were about to see the azaleas bloom. Well, last Saturday night, it got down into the teens and killed all the azalea flowers. It also killed a lot of trees' leaves that were still small and tender. But the interesting thing was what happened to a poor crape myrtle on one side of our driveway.

Apparently the roots of the crape myrtle didn't get the message that it was cold, and kept pumping sap into the branches. Then the branches froze and cracked, and the sap kept oozing out and froze into these ribbons of ice. Dad had never seen anything like it, so he and Jeff took a whole bunch of pictures of it. Dad showed it to one of his colleagues last week, who referred him to this page with pictures of this phenomenon, also taken in Tennessee.

I think that the crape myrtle is probably dead, unfortunately. And our beautiful spring got wiped out. Plus we had to get out our winter clothes again. But it should be over soon (I hope).

Wednesday, April 11, 2007

My Visual DNA

News Flash!

On Thursday, we took Vinny for his six-month checkup. He weighed 19 lbs and was 27.5" in height. The doctor gave us permission to go ahead and give him some green veggies. She asked if he was sitting up on his own, and we told her that he wasn't yet. She urged us to prop him up and kind of tripod him with his hands on an interesting toy.

Well, on Sunday he just decided to start sitting up, hands-free. The day before, he couldn't even sit up on his own. Then on Sunday, he could sit up and stay seated without the help of his hands!

If he leans over too far, he will fall, but really you can leave him seated on the floor and he will stay like that for quite a while. I am just amazed by how fast this development came!

Saturday, April 07, 2007

More Good and Evil

I entitled my previous post "Good and Evil," because that's the subject I really wanted to discuss. Instead, I realized that the post was getting rather long after I'd written up the two psychology experiments, so I decided to split it into two posts.

I think that Zimbardo's and Milgram's experiments demonstrate a couple of important points. The most obvious conclusion is that good people will do bad things under certain conditions, but the experiments contain rudimentary notions of unhealthy deference to authority and apathy of the subjects in both experiments after their part in it was over.

Both of these subtleties are most clear in Milgram's experiment. When the "teacher" expressed a desire to quit shocking the "learner," the so-called supervising scientist simply said "Please continue," and many times, that was enough to get the teacher to keep going. The remaining three verbal prods, in order of increasing pressure, were "The experiment requires that you continue," "It is absolutely essential that you continue," and "You have no other choice, you must go on." The scientist never intimidated, never threatened the subject; just simply expressed that he/she needed to continue the experiment. And for 65% of the subject population, that was enough prodding to ostensibly kill another human being with electrical shocks.

And while 35% of the subjects put a premature stop to the test, none of them tried to get the experiment as a whole shut down. There were no calls to the Psychology Department Chairman, no letters of complaint to the University, no news stories about the cruel experiment that Milgram was performing.

I'd like to think that I would be one of the 35% who put a premature stop to the test. There was one variant in which the learner mentions his heart condition in passing, and I'd like to think that if I had been the subject of that test, I wouldn't have shocked him at all, out of consideration for his heart condition.

But statistically speaking, I would probably be one of the folks applying shocks to the end. And I don't think that anyone refused to shock him because of his heart condition, so I doubt that I would distinguish myself there, either. After all, there is nothing setting me apart from everyone else.

The implication of these experiments on human behavior is profound. They make it very clear that the reason I have not committed any crimes is not because of any moral superiority on my part, but rather because I have not been in circumstances that would prompt me to commit crimes. I've never been placed into authority with no accountability (as the guards in the Zimbardo experiment and the guards at Abu Gharib were, according to Zimbardo); I've never been asked to do something so contrary to my morality (as the subjects of the Milgram experiment were). I've lived a very dull but safe and stable life. If I had been brought up in an unsafe, unstable place, things would be very different for me. I can see myself ending up as a murderer, a drug addict, or even a terrorist depending on the scenario.

It's not a stretch to take away from this the message that circumstances profoundly shape people's lives. If you were born to an indigent family in a poverty-stricken country that had been bombed into the stone age and had its natural resources exploited by the United States, you'd better believe you'd grow up chanting "Death to America!" Who wouldn't be pissed that some other country was prospering off the ill-gotten gains they acquired by taking advantage of you?

It's for reasons like this that many people regard the United States as the cause of its own problems with terrorism. Our foreign policy has created many of the world's political hotspots.

But the take-home message is that in order to cut down on the amount of evil in the world, we need to understand the circumstances that lead people to commit evil acts, and then work on preventing those circumstances from befalling others. For example, if people steal because they don't have enough food, then it seems obvious that ensuring that they had enough food would cut down on stealing. If people get caught in the spiral of poverty and end up committing crimes, then it would make sense to provide adequate educational opportunities, physical and mental health facilities, and activities that would help them get out of that cycle.

Wouldn't it be nice to give would-be muderers, drug addicts, and terrorists the opportunity to become law-abiding, happy, fulfilled citizens instead? We can do that by altering the circumstances surrounding their lives.

Good and Evil

In the summer of 1971, nine college-age men with no criminal records were arrested on charges of armed robbery and imprisoned in Palo Alto County Jail. Their crime? Signing up for a study on the psychological effects of prison life, conducted by Professor Zimbardo of Stanford University.

Nine other volunteers (also college-age men with no criminal records) were involved in the study, on the other side of the bars, as guards. They were assigned in threes to work eight-hour shifts as guards for the makeshift Palo Alto County Jail (actually in the basement of the Psychology building at Stanford).

The website I linked to in the first paragraph is Dr. Zimbardo's own website about the experiment, and I'd encourage you to take a look at the slideshow about the experiment.

The experiment was slated to run for two weeks, but it was halted prematurely after only six days, because of the horrifying transformation of the "prisoners" into subhuman monsters or psychological basketcases, the "guards" into brutal authoritarians, and Zimbardo himself into prison administrator! Basically here's what happened: The situation into which each participant was placed transformed him into filling that role, despite his lack of criminal record, authoritarian credentials, or prison administrator experience. Zimbardo was particularly horrified by how even he had been changed, going from research psychologist to prison superintendent. At one point, when he heard a rumor that the prisoners were planning an escape, instead of "record[ing] the pattern of rumor transmission and prepar[ing] to observe the impending escape," he took steps to foil the escape![*]

Another seminal experiment in social psychology was conducted by Stanley Milgram at Yale University. After World War II, Milgram wondered what drove Nazi war criminals such as Adolf Eichmann to perform such cruel acts. So he formulated some experiments to answer the following questions: "Could it be that Eichmann and his million accomplices in the Holocaust were just following orders? Could we call them all accomplices?"

The Milgram experiment "measured the willingness of study participants to obey an authority figure who instructed them to perform acts that conflicted with their personal conscience." Participants were told by the supervising scientist that the experiment was testing the effect of punishment on learning. They were to be the "teacher," using electric shocks to teach another participant (actually a confederate), the "learner," some sets of words. The teacher and learner were placed in separate rooms where they could communicate but couldn't see each other. If the learner got the words wrong, the teacher was to shock them, and the voltage went up after each wrong answer. The teacher was given a reference shock of 45 V before the learning experiment began, so that he/she could know what the learner was experiencing.

In reality, the learner in the other room experienced no shocks. But he knew the voltage of the shocks being administered by the teacher, and acted accordingly, screaming, rapping against the wall, and when the voltage exceeded a certain threshold, no response to the question and no further complaints.

If at that point the teacher wished to stop, the supervising scientist told him/her to continue, using verbal prods of increasing pressure with each protest. The experiment stopped after the teacher still wished to stop after four verbal prods, or after the teacher had given the maximum 450-volt shock.

How many people administered the 450-volt shock? Surely only the most psychotic people would be cruel enough to do such a thing to a suffering human being! In fact, 65% of the forty subjects of the first experiment administered that 450-volt shock, although most were uncomfortable or hesitant to do so. But with the prodding of the supervising scientist, they administered the shock even though it clearly conflicted with their conscience. Interestingly, while many offered to return the check they were receiving for participation in exchange for quitting the experiment, no one demanded that the experiment as a whole be stopped.

These experiments show that good people can be placed in situations where they will perform evil acts. But I think there are a lot more interesting conclusions that can be reached from these experiments, and I will talk about them in my next post.

Wednesday, April 04, 2007

Weekend Fun

This past weekend, Dad and Marvis stopped in for a visit. They were on their way to the beach for Spring Break, but stopped in to see their youngest grandchild (and their daughter and son-in-law too). They arrived on Saturday afternoon and left on Monday morning. Saturday evening we invited our friends Adam and Jody to join us for dinner, so they could meet each other. Jody brought her world-famous chips and salsa. Jeff made Italian roasted pork loin, red potatoes with rosemary, salad, and glazed carrots, and I made cornbread. For dessert we had strawberries and ice cream. We moved our dining room table outside, and ate on our deck.

On Sunday, we had planned to go to the Smokies, but it was raining so instead we went to the American Museum of Science and Energy, right here in town. I visited it once when I was a teenager, but hadn't been back since, so it was good to go to it again. I enjoyed the museum and I think it's a great resource to have here in town as Vinny grows up.

Vinny was his usual charming self and his grandparents oohed and aahed over him, and fought to get the chance to hold him, feed him, and even change his diaper. As far as I'm concerned, that's great! I've changed plenty of diapers and I don't feel deprived about forgoing the pleasure in favor of his grandparents.

I left for work early Monday morning before Dad and Marvis got up, but I think they were sad to leave, and looking forward to their next visit with their grandson.

More Migraines

Yesterday I had another migraine. It started at 12:30 p.m., right when I was heading off to lunch. So I couldn't hardly see the food I was selecting in the cafeteria (not that it mattered; it is all pretty much nasty), and I had to get the cashier to pull the money out of my change purse to pay for my food, because I couldn't see well enough to differentiate between the denominations of bills. After lunch, I called the doctor's office, and they let me come in for an appointment at 2. Luckily by that time I could see well enough to drive to the appointment, although I had a splitting headache. The doctor prescribed some medication for me to try the next time I get a migraine. I hope it works better for me than the other type that I tried when I was a grad student (i.e., better than "not at all").

After the appointment, I came home and slept for about three hours. Then I vegged for the rest of the evening before going to bed. Last night we had a huge storm that kept me awake for several hours. But it didn't faze Vinny. He startled slightly during the loudest thunderclaps, but they didn't wake him up.

Today my head was still painful but not as bad as yesterday. I got some work done despite the pain.