Friday, October 31, 2008

Bouncy Bouncy

As a physicist, I can't resist the analytical approach of the work of baseball analyst Nate Silver at Below is a graph of data from his projections from mid July through Thursday, October 30, five days before the vote. Although this might pass as his "prediction" of the outcome, my interest today is in the dynamics of this function. We can all look at the last few days of polling and the final - actual - poll about a week from now.

The curves indicate the projected electoral vote count from his analysis (more on that below the fold) with a few key dates flagged on the graph. The red arrow near the middle is the day Sarah Palin was announced as McCain's VP choice. The green brackets on either side span the Democratic and Republican conventions, respectively, while the green band with red lines indicates when the four debates took place. The VP debate (2nd of the four) is shown with a longer line.

You can clearly see the "bounce" from some of those events, but it seems to be delayed by a week or two. I don't know how much of this is the time it takes to execute a poll, how much is due to the damping factors Nate has in his model, and how much is due to the time it takes human beings to process information.

By the way, the now-infamous Katie Couric interviews started airing on September 24, just a few days before the first Presidential debate, so it really can't be separated from those other events.

What interests me is that large delay between what have been identified so far as 'critical' events and the response of the dynamical system. An engineer would probably say there is a lot of 'lash' in the system. If so, is there really any justification for all of the money spent on insta-polling right after a debate or a convention? Doesn't look like it to me.

The "bounce" that Obama got from his convention started before the convention (all that lead-up talk?) and continued on for at least two weeks, right through the Republican convention and beyond. The short-lived bounce that McCain got from his VP pick and his convention (one week going up and then one week going down) was also delayed by at least one and maybe two weeks. (For reference, the tick marks on my X axis are 14 days apart.)

You can certainly see that the electorate has settled in after the last debate, with only small statistical fluctuations over the last month. Of course, these are people, not a mechanical system, so only time will tell what they will actually do and what changes might occur between now an election day. However, it is also true that a lot of those people have already voted.

Nate Silver's analysis

Read his FAQ for details.

I've been following Nate's work with great interest. His Monte Carlo technique for simulating the results of an election are common in the world of physics, where they are used to simulate physical systems ranging from quark-gluon interactions to atoms in a lattice (such as a silicon chip) to the flow of radiation during the explosion of a nuclear weapon. His maps (see below for a sample) are based on the analysis of individual states, but his overall prediction of the electoral vote count summarized above comes from a simulation. He produces 10,000 "elections" by a Monte Carlo process, picking a possible result for each state based on the odds that it will vote for a particular candidate (as determined by his analysis of all polls in that state, their interaction with national polls, and a projection toward election day). This incorporates the inherent "fuzziness" of the poll numbers, which each come with a substantial sampling uncertainty.

This is a very powerful technique, since it replaces individual interpretation of those uncertainties on a state-by-state basis with the blind sledgehammer of massive statistical sampling. This method has proved extremely effective in experimental physics, particularly experimental high energy physics, for predicting what reactions will look like in a new detector and determining if the needle of a new particle can be found within the haystack of normal events.

The one caveat, of course, is GIGO. Nate is not a pollster, he is an analyst of polls. His results are only as good as the polls themselves, despite his attempts to have his model learn about and account for the individual characteristics of those polls. But how can he (or even a pollster) account for my decision this evening to blow off someone from the U of Iowa polling about my attitudes about the election because I didn't feel like giving them a quarter hour of my time? Must drive them nuts.

Techy detail update:

My quick guess is that his half life is responsible for some of the 'lash' in the response of his model to the driving force of various campaign effects, but that the rest is due to processing time by the electorate. Even with the trend-line adjustment of a given pollster's data, his model requires some some time to reflect sudden changes in the views of voters. Although this might hide last-minute changes, all of the raw poll data are shown for any given state along with his model's analysis of those data, so you can draw your own conclusions about, say, Pennsylvania.

Finally, for reference, the projected electoral map from Thursday is shown below.

This projection, and all of the data in the graph at the top, comes before his final fine-tuning of the model to include a 2-week half life.

Read Entire Article......

Saturday, October 25, 2008

Bless her Heart

Thanks to The Thomas for this one ...

In amongst a lot of political blather, 'Rachel' writes about her First Chemistry Exam Results. This is quite long, so it all goes below the fold.

Some may say a B is not bad, but it is bad when you should have had an A and the reason you don’t have an A is because you are a pathetic, ridiculous, quantum singularity of a dumbass.

Two of the three questions I missed? Want to know what they were? Do ya? Ready to lose every shred of respect you may possibly have had for me? SIGNIFICANT FIGURES. ....

But like I said, it’s all relative. They say this is a weed-out course and they ain’t kidding. Professor gave us the scoring breakdown, and dude. Kids. Put down the bong and hit the books.

Total number of students: 192.
Average test score: 61.2%.

There were 25 A’s, 31 B’s, 20 C’s, 37 D’s, and 79 F’s.

Observation 1: Sig figs.
If you get the significant figures wrong, the patient dies or the bridge falls down. However, if that is all you get wrong under test conditions, you'll probably get an A once the HW and other exams are all taken into consideration and do just fine in your eventual career.

Observation 2: Grade distribution.
That failure rate is a pretty familiar situation. [I think I've mentioned before that 30 to 40% of my students fail intro physics, mostly for the reasons related to study habits and basic math skills.] Their previous classes, either basic college courses or high school classes, did not require any independent study because they had lots of homework time in class plus extra credit opportunities and a curve. Much of this is due to the fact that HS teachers are simply not allowed to fail more than a few students, if that, so any kid smart enough to go to college has never been at risk of failure in HS. The standards in college are different, however, once you get past the HS courses we teach in college. See my blog about what needs to be said during Orientation.

Observation 3: Political intro.
Rachel carries on at length wondering, among other things, why David Letterman thought that a badly run campaign might be warning us of a badly run government: "is he actually comparing a campaign to the presidency?" Sure. A campaign is a lot easier than the Presidency. If your management skills can't handle that part (and managing their respective campaigns is the only major management experience either McCain or Obama have had), it is sort of like not being able to handle intro chemistry when you want to be a Physician. Weed them out, sooner rather than later. If Snowflake (see below) can only resort to attacking the other kids (say by spoiling their lab experiments, as sometimes happens) rather than improving her own performance, we really don't want her as our doctor. Or President.

More recently, 'Rachel' writes about the Second Chemistry Exam Results

That’s not a typo. MORE THAN HALF THE STUDENTS FAILED THE TEST. And yet a score of 88 is not an A. Boo!

I understand the concept of a weed-out course, I really do. I understand that if you curve it, people will stay in who maybe shouldn’t stay in. I get it. But for the pity of St. Pete! I still am annoyed! Mostly at self but whatever.

I still have an A in the course overall because each test is only 10% of the total grade, and I’m averaging high 90’s in homework and lab. So I’m kinda making chem my bitch. She’s coy, though. Elusive yet attainable.

But these kids in my class, good Lord, these kids. I pity whoever is paying their tuition. In lab Friday, they were all discussing the test scores. None of them got higher than a 70 on the test. One girl said she got a 49, and she was all kinds of distressed. I shit you not, here is an actual quote from this girl, which she said with a truly flabbergasted look on her face:

“I don’t understand it! I studied for four hours!!!! God, what does it take to get a passing grade?”

Oh, honey. You adorable little snowflake, try four solid days, 8 hours each. This isn’t high school, in case you haven’t noticed. I bet your Daddy noticed when he paid your tuition bill, and I bet he’ll be very excited when he sees your grades. What a sound investment you are.

Observation 0:
I also quickly learned that whenever I was annoyed at a particular class or instructor, I was really annoyed at myself.

Observation 1: Weed out course.
If you curve it, people will stay in who will end up standing over you in the Emergency Room wearing a name tag that says "MD" on it that only know half of what a doctor is supposed to know. Or you will end up driving over a bridge that was designed by someone who needed extra credit or curved grades to become an engineer. (Since the failure of the I-35 bridge in Minnesota was due to a design error, this last possibility might hit closer to home for some people.)

Observation 2: Studying for a week.
The correct approach is neither cramming for four hours [?!?!] the night before the test or 32 hours over a week, it is to study regularly and diligently for 1 to 2 hours every night, including weekends, every week for that 3 credit class. The key is retention of this prerequisite material, both for the long term (years) and so that you don't have to cram for three weeks for the final exam because you forgot everything from exam 1 and exam 2 in the meantime.

Observation 3: Lots more politics.
But then Rachel tries to assign motives to these rich kids who don't have to work their way through school, or even work to pay for their car or phone, as if the majority of parents/voters from wealthy suburbs are all liberal Democrats - and misquoting Sen. Obama along the way.

I told her I’m the youngest of four and my parents started with nothing themselves and that I never expected them to pay for my education or anything else once I turned 18, and she gazed at me like I was speaking Chinese.

What the hell? Have 18-year-olds these days never heard of “a job”? Or of “taking night classes for 10 years”? Or of “going into assloads of debt because no one’s holding your hand but it’s worth it because then you are the boss of your own self which is pretty awesome”?

Gah. Honestly, it just boggles my mind, how much people take it for granted that someone else is going to take care of the hard stuff for you, not to mention why you’d want them to. I’ve been on my own since the day I graduated from high school and frankly, this is the main reason I get so magnificently resentful of shit like what Obama said about “spreading the wealth”, and about how so many liberals think that anyone who’s against spreading the wealth is just a greedy fucker who wants to hold on to the things he or she was “given”.

First, Obama was talking about cutting your taxes, Rachel, so you would have more money to spend (spread around) on things like your education. You should read what he actually said, which is quite different from what various prevaricators and spin-meisters have implied that he said. [You can read it at the bottom of this article.] Less in taxes from working families means more money in the consumption part of the economy, so more money that can flow into the hands of self-employed small business owners like yourself. The argument is not about whether there should be a tax cut, it is about whether the tax cut should go to millionaires or to the middle class. The argument is not about whether government should redistribute wealth, it is about whether it should transfer it from poor to rich (as has been the case recently) or from rich to poor - or from future taxpayers to today's taxpayers. It is about whether "supporting the troops" means buying a yellow magnetic ribbon while borrowing money from your grandkids, or paying taxes to pay for their well-earned benefits.

Second, the entitlement mentality you write about is, in my experience, most common among wealthy students from the (mostly) Republican suburbs. They are the ones who talk about supporting our troops but scream if someone asks them to pay even one more dollar in taxes to actually support those troops, and then call it Socialism when you "give" those veterans a bigger GI Bill package to "spread the wealth". I never see it among the working class students at my CC. They are too busy working and studying to get ahead to whine like Ms. Snowflake. Too much to even figure out if FICA plus income plus sales plus property taxes adds up to a larger fraction of their income than it does for Donald Trump.

You see a very different picture at a community college, with a mix of suburbanites and working students and returning students, than at a university where they teach chemistry to 200 students at a time. It might seem odd, but the guy who works a full time job before coming to my class is always wide awake, prepared, and fully engaged. The guy who can't quite get out of bed for a class at noon, coming in a half-hour late and sometimes falling asleep in his afternoon class, isn't working nights. No, he lives at home in Exclusive Suburb and doesn't have a job.

Finally, read what Obama actually said rather than the sentence fragment that made it into the news:

The correct, complete quotation from Obama regarding "share the wealth" is

"But what’s happened is that we end up – we’ve cut taxes a lot for folks like me who make a lot more than 250. We haven’t given a break to folks who make less, and as a consequence, the average wage and income for ordinary folks, the vast majority of Americans, has actually gone down over the last eight years. .... I just want you to be clear – it’s not that I want to punish your success – I just want to make sure that everybody who is behind you – that they’ve got a chance at success too.”

... snippage ...

“And I do believe for folks like me who have worked hard, but frankly also been lucky, I don’t mind paying just a little bit more than the waitress that I just met over there who’s things are slow and she can barely make the rent."

Obama said, "My attitude is that if the economy’s good for folks from the bottom up, it’s gonna be good for everybody. If you’ve got a plumbing business, you’re gonna be better off if you’re gonna be better off if you’ve got a whole bunch of customers who can afford to hire you, and right now everybody’s so pinched that business is bad for everybody and I think when you spread the wealth around, it’s good for everybody."

Emphasis added. Notice that he is saying that giving an N billion dollar tax cut to 5% of Americans is unlikely to generate as much business for someone like Joe the Unlicensed Plumber as giving that N billion dollar tax cut to 95% of Americans. More money for small business owners rather than more money for a few CEOs.

Anyone who thinks the few persons whose business profit (not revenue, not the value of the business, profit) exceeds a quarter million dollars a year are fellow members of the working class is getting conned, big time.

Read Entire Article......

Tuesday, October 21, 2008

Holiday Catalogs!

Monday, Oct 21, marked the arrival of the first Holiday Catalog of the season ... that I noticed.

Today, three more arrived. I sense a trend.

Remember last year?

Should I repeat the exercise this year?

I'm worried that I missed some earlier this fall, messing up the data collection process, but it could be that they held off because of (a) the massive election mailings or (b) the economy or (c) I did not notice the first ones because of the massive election mailings.

Read Entire Article......

Monday, October 20, 2008

But the Answer was Right!

The cry of the Lucky Equation Grabber.

Not a relevant issue when the solution was wrong.

I grade the solution, not the answer.

This is a physics class, not a lucky guess class.

You can imagine the wailing and gnashing of teeth, but (as I wrote in the comments in a related thread over at Becky Hirta's) if you wanted to take the class from someone who doesn't care if you learn the physics, you went to the wrong place.

You need to be over at Wannabe Flagship where they give multiple choice tests and let kids use a crib sheet for F=ma and the other 100 equations you can derive from it, one for each possible problem on the exam.

They also don't notice that two algebra errors resulting in a correct answer equals two errors, not zero errors. I do.

Read Entire Article......

Sunday, October 19, 2008

Paying for College - An Anecdote

Dr. Crazy wrote a fantastic article Friday on Paying for College. Her comments on a NYTimes article about some poor family struggling to put two kids through private schools after losing a big part of their 100 k$ income. [At least that is what the article implied; it could be that was their post-layoff income.] I'm sure it is a strain on them, but if their two kids actually got a quarter million dollar's worth of education, I'm sure they will pay those extra loans off in no time. Maybe.

But I don't think any of my students would be particularly sympathetic to someone who chooses to pay $32,000 and $29,500, respectively, for each year of college. One, in particular, probably finds these folks to be whiny elitists. Compare the following:

One child is attending a college with only 1000 students, total. Fewer than lived in one dorm where I went to college and got a degree of outstanding qualtiy. Fewer than we admit each year as FTIC freshman college students at Ishkabibble CC. Yet, despite the serious financial load, the article made no mention at all of the kids helping out by working.

Another child is attending my CC. He has a problem, too. He is assigned to me for advising for next semester (his second in college, a critical point in his education) and contacted me about an appointment. I proposed one convenient slot, in the hour before one of his classes meets, but he can't make that one because he works from 6 AM to 2 PM every day, getting off work just before heading to his afternoon class. Yeah, that makes it pretty tight. Fortunately, there is one day when we can get together between his afternoon classes and his evening classes.

I hope the first kid appreciates what he is getting. The second one can only take 9 hours of a classes because of his work schedule, so he doesn't even qualify as a full-time student for financial aid (or as one of our FTIC statistics.)

Read Entire Article......

Wednesday, October 15, 2008

Clue for sale

So I teach two main classes: first semester physics and second semester physics. Rather obviously, passing first semester is required before you can take the second semester. Right?

Early registration is starting for the spring semester, and the second semester classes are filling up. So what do I see?

Several students who have registered for the second semester who have yet to pass (even with a D) an exam in the first semester course.


Your wonderful optimism is messing with our planning process.

Read Entire Article......

Thursday, October 9, 2008

Quantum Crypto

Nice little article from the BBC today about a practical realization of quantum cryptography.

I particularly liked the line where they conclude that maybe God does play dice!

I don't have the time to write much more, but I will add one thing. Over many years, the most amazing thing about quantum mechanics has been the way it has passed experimental tests of the most arcane predictions. I say that not only because these tests confirm some rather odd physics, but because simply doing them at all has taken truly outstanding skill on the part of experimental physicists.

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10/09/08 07:06:05.04030201

OK, it only works with an American calendar system, but all sorts of fools push numerology of some sort based on some strange premise.

So at a few minutes after 7, when this is scheduled to appear, we'll have a countdown date and time.

Let's just hope the markets don't crash - again - at that moment.

Read Entire Article......