Sunday, April 21, 2013

Tom Lehrer

No prophet is accepted in his own country, it's said -- and yet oddly enough, nearly fifty years ago there once was a man by the name of Tom Lehrer -- erstwhile Harvard mathematics professor, wry songster, and television parodist -- who managed to make music out of some of the most irksome and intractable issues of his day. Racism, pollution, Jim Crow, pornography, the nuclear arms race, the Second Vatican Council, and even World War III were all fodder for his astonishing show tunes, and there often seemed to be scarcely any line of propriety he wouldn't cross. And yet, since he sung every one with such verve, he managed to make nearly everyone laugh at their own folly, rather than throw rotten vegetables at the stage. By the late 1960's, his songs were the stuff of legend, exchanged by high school and college students like a sort of secret code: do you know "The Vatican Rag"? "Poisoning Pigeons in the Park?" "Smut?" At my high school, all the cool kids (that is, all the geeks, since I went to an alternative hippie Quaker school) had at least one of his songs memorized.

It was amazing to me and my friends in the late '70's and early '80's to think that many of these songs were first heard on network television in 1964 and 1965 on a program called That Was the Week that Was. You'll have to remember, this was a long, long, long time before Stephen Colbert.

Lehrer retired from comic songstering for more than 25 years, re-emerging briefly at a concert in 1998, where he was introduced by his old friend Stephen Sondheim, and performed a lovely redux of his famous anthem Poisoning Pigeons in the Park.

Since then, he seems to have re-retired, though I have it on good authority that he still lives in -- or at least is occasionally seen near -- Cambridge, Massachusetts. Asked in an interview some years ago why he wasn't writing songs satirizing our present moment, he observed that these days,  "everything is so weird in politics that it's very hard to be funny about it." True enough.


Tuesday, April 16, 2013

The Problem with Evil

The word "evil" seems to be trending once more. It's a harsh word, a powerful word, a sweeping word. There's no way to dilute it or qualify it; a person or a deed can't be more or less evil, just a little evil, moderately evil -- it's all or nothing. We reach for it in the same way we reach for the emergency brake switch on a train -- as a last resort, knowing that pulling that switch will be an irrevocable act.

"Evil" works for us when nothing else will. Like a pair of asbestos mitts, it enables us to handle things we could otherwise not bear to touch. "Evil" enables us to categorize and keep safe distance from people who would otherwise almost crush us with their horror, their unfathomability: Hitler, Stalin, Pol Pot, Idi Amin. And it gives us unlimited power to denounce them, to condemn them, to convince ourselves that never, never, never would we have anything to do with them. Those who are "evil" are consigned to the world of devils and demons, the underworld of those whose motivations, personalities, influences, or thoughts no longer matter. How could they? -- they're evil.

But "evil" also blinds us. It convinces us that, while some judgments are just a matter of perspective or cultural context, others are absolute, and apply universally. And yet when, in re-creations such as that in the film Argo, we see the United States denounced in billboards as "The Great Satan," we smirk and think how ridiculous that is: "What, us, Satan?"

And this is the essential problem. In the relentless march of cultural and historical amnesia that our modern media-saturated world embodies, "evil" is the ultimate memory zapper. It convinces us that all we need to know about someone is that they were "evil" -- no more sense learning about their lives or motivations. Case closed. The fact that so many of the people we write off in this manner were, in their country and in their heyday, beloved by millions and widely admired, strikes us a irrelevant. The fact that so many people who ended up being "evil" started out being "good" seems merely an inconvenient detail. When we see women holding up their babies for Hitler to kiss them, or families weeping at the funeral of Kim Jong-il, we think to ourselves, what foolish people! How were they so hoodwinked?

But perhaps it is we who wear the blinders. "Evil" works so well in retrospect; it solves for us the problem of history. But if we really want to prevent future Hitlers and Stalins from arising, it's absolutely useless.  No one steps forward and calls themselves evil -- to do that would be almost comic, like Austin Powers or Aleister Crowley. No, the people who we may, eventually, find to be evil will always be people who arrived to meet some human wish or another: the wish for stability, the wish for prosperity, the wish for revenge, the wish for power. They will begin by being very attractive people indeed, so attractive that we don't see them in time to stop them -- or ourselves.

Friday, April 5, 2013

Robo-grading

"Essay Grading Software Offers Professors a Break," read the headline in the New York Times. With the usual fanfare according some new and seemingly innovative educational development, the article described the new system developed by edX, a nonprofit corporation set up and sponsored by a group of √©lite colleges and universities, and which was (until now) best-known for developing software for, and hosting, MOOCs.  The president of edX, Dr. Anant Agarwal, is an electrical engineer (of course!) and has overseen this new system with the goal of 'instant feedback' in mind.  After all, who wants to wait for a professor to diligently grade an essay by hand, a process which can take -- if you have 25-30 students in a class, as I often do -- a week at least, and sometimes more -- especially when you can get it "graded"instantly online, and instantly work to "improve" it. All of which raises two questions: 1) What is it that professors would be "freed" to do if they didn't do one of the most essential tasks of teaching? -- and 2) How can a computer possibly give meaningful feedback on an essay?

But it's not the first time. Years ago, there was a little test which would, like magic, determine the "readability" and grade level of an essay; it was called the Flesch-Kincaid Grade Level test. It was based on two things that roughly -- very roughly -- correlated with readability and sophistication -- the length of sentences (surely longer ones were more challenging to read) and the length of words (given that many technical and specialized words of more than two syllables are derived from Latin or Greek, this again offered a sort of metric. Of course one could write none but brief words -- low grade level! Or someone preparing to compose a disquisition upon some substantive matter of polysyllabic significance could readily simulate the species of composition that would elicit a higher plateau of evaluative achievement. Not surprisingly, the Flesch-Kincaid test was initially developed by the US military in 1948, but it took on a new life when Microsoft Word included its metrics as an add-on to its built in spelling and grammar checker. By its metrics, the lowest-rated texts would be those packed with monosyllables, such as Dr. Seuss's Green Eggs and Ham, while a long-winded theological or legal treatise loaded with multi-syllable words word score high.

So how does edX's system work? Not surprisingly, it takes a page from the neural network systems developed years ago at MIT to handle complex tasks like parsing language or manipulating a robot hand. The idea of a neural network is that it programs itself by repeating a task over and over, getting feedback as to the success of each result.  When the feedback is good, the network "remembers" that behavior, and prioritizes whatever it did to achieve it; when feedback is bad, routines are dropped, or changed and tried again. It's not unlike the way babies learn simple motor skills.

And so, in order to judge whether an essay is "good," the edX system asks for 100 essays, essays already graded by professors. It internalizes all the patterns it can find in the essays marked as "good" or "bad," and then tests itself by applying these to additional papers; if its results match those of the human graders, it regards that outcome as "good" and works to replicate it.  Of course, such a system can only possibly be as good as whatever the professors who use it think is good; it might well be that what is good at Ho-Ho-Kus Community College is not so good at Florida A&T or Cal Poly. And the demands of different assignments might demand different metrics, or might even vary over time; such a machine would need regular re-calibration.

But can such a computer program be said to really be evaluating these essays? No. It only works to be predictive of the grade that a human grader would tend to assign. And, with so-called "outliers" -- papers that are unusually good, or unusually bad, its rate of error could be quite high. If we imagine a paper which breaks the usual rules of writing in order to obtain a certain effect, such a paper might indeed get very high marks from a human grader, but be flunked by a machine which believes there is no such thing as a good reason to violate a grammatical or structural rule.

So we're back to square one. If there were a large lecture where a standard sort of essay was expected, with very strict parameters, a program like this might be effective at matching its assessments to those of human evaluators. But this isn't how any college or university in fact teaches writing; in the best programs, the classes are small, the assignments varied and often have elements of creative writing, and the level of individual attention -- and variation -- is high.  Replacing professors in these classes with robo-graders would almost certainly result in much poorer learning.

And what are we freeing these professors up to do? What higher calling awaits those "freed" from grading essays? Recent surveys show that the average tenured or tenure-line professor in higher education today is teaching fewer classes than ever before; the figure was once over three courses per semester, and is now falling closer to two. Of course, at some smaller liberal-arts colleges, such as the one I teach at, our standard load is three; I myself teach four a semester, as well as four every summer -- twelve courses a year in all (hey, I've got kids in college myself, and I need the "extra" pay!). And somehow despite all that grading I've managed to write three books and dozens of articles. While, at the big research universities, some professors get so much course relief that they teach as few as two courses a year -- over my career, I'll have taught more courses that six such professors.  So I don't think the argument holds that professors need to be "freed up" from anything, unless they're teaching multiple large lectures, in which case they doubtless have teaching assistants anyway.

So go ahead, robo-grade your papers. Give your lectures to a video camera and have everyone just watch your MOOC. At that point, you don't really need to be on campus anyway, so why not just take an extended vacation?  But if the parents who are laboring and borrowing to gather up the funds to pay the tuition that pays your salary start to feel that your vacation should be a permanent one, don't be surprised.