I visited my mailbox this morning to pull out the exams that students have turned in. I leafed through the exams, and saw that the students were speaking at length and with passion and expertise about parsing, activation records, semantic analysis, code generation --- all of the courses one expects at a 5-star compiler banquet.

I was taken back to my days at Rice when I studied these topics with Ken Kennedy, of blessed memory. The thought that these students now know what he taught me gave me one of those rare I-Thou moments.

As the Olympic torch makes its way to Beijing, a torch of a different kind passes from generation to generation. It's worth stopping to notice this.

Some years ago, when I worked for IBM, a business trip took me through the United Airlines terminal at Chicago's O'Hare airport.

O'Hare is one of the world's busiest airports, and United is one of their biggest customers. Two of their concourses, B and C, are actually in separate terminals (1 and 2). Because they are so far apart and because connection times between flights can be short, a tunnel was constructed between the two.

As you can see from its photos, this is no ordinary tunnel. There are neon lights that flash in progression, and music suggestive of Rhapsody in Blue, the United Airlines theme piece, accompanied your transit through the tunnel. You could walk through the tunnel or take a moving walkway to make the trip a bit quicker.

On my first trip through the tunnel, I was completely unprepared for what I was about to experience. It's easy to become jaded about air travel, and to acquire a certain numbness when flinging between cities and traversing airports. This tunnel had a profound effect on me, and made me reawaken to the wonders of flight.

On every trip since, through O'Hare on United, I have sought out the tunnel between flights, even if I didn't need to connect between the terminals, just to have the tunnel experience.

I did so yesterday, as I flew through O'Hare from St. Louis to Moline, where I would then drive to Iowa City. I was very disappointed to see that some of the neon lights were not functioning -- these hang overhead and usher your way through the tunnel. Also, there was no music at all -- no eerie tones or fragments of the Rhapsody. All you could hear was the drone voice telling you to look down, as the moving walkway was about to end.

Chicago, United, O'Hare -- your neglect of this previously eye- and ear-opening experience is appalling. This year is the 20th anniversary of the completion of the tunnel. Can't you work on it a bit and restore it to its original magnificence?

See this for a simple experiment that yielded an amazing result: butterflies remember things from when they were caterpillars.

In this morning's paper, there was a story about people who are wanted for robbery, for whom no warrant is issued. These people are sometimes stopped by police in other states, but since no warrant is outstanding, they're let go and not brought to justice for their crimes. The city (St. Louis) has some rule about having to question somebody before a warrant is issued. If the person in question doesn't show up for the hearing, no warrant, no nothing.

Meanwhile, in this same city, if somebody has a traffic ticket, and owes the city money, a warrant is issued, and the person is not only picked up, but thrown into jail until the ticket and all the outstanding fines are paid, sometimes involving thousands of dollars for just a few tickets. This is done if the person is deemed a flight risk and might not pay up.

Why are the rules so different for simple traffic tickets (non registration, speeding) as compared with real crime (robbery)? In one case, the city benefits from having the tickets paid. In the other case, the victim of the robbery could have a measure of justice.

Thanks to my students, I learned about retronyms a week or so ago. For those too tired to click, an example of a retronym is the acoustic guitar, which was formerly called just a guitar until its electrified cousin came along and a retronym was needed to distinguish the two. World War I is another example. At the time, nobody had the foresight to start enumerating the war(s) to end all wars.

So I throw down the gauntlet -- what will be the next retronym? Human professor? Terran apartment? Nonvoluntary income tax?

And what happens when an oxymoron meets a retronym? Do they beget an oxynym or a retromoron?

We as a department are in the midst of some interesting changes in the way we approach teaching. I have an open mind about most of what we are considering, and on a few points I have no set opinion yet. I post this entry in hopes that people will respond with how they see the issues I raise. Some of what we are considering has been inspired or adapted from studies on Active Learning.

In summary, one aspect of our change is to move from in-class lecture to lectures that are meant to be viewed before coming to class. The prerecorded lecture can be watched at the student's leisure, and with appropriate indexing it should be possible to move around, skip, or review portions of the lecture. Except for control of the point in the stream, the experience is meant to be noninteractive.

In class, instead of having lecture, students work on problem solving, perhaps in groups, with the problems as motivation for truly acquiring and extending the lecture material. As needed, the professor can offer parts of lecture in review (live), but mostly the professor is guiding the students through an active learning experience, where the students learn by solving problems.

In effect, the role of lecture and homework are switched. Formerly, lecture took place in class. I try for a very interactive form of lecture, with students asking questions and guiding the depth and form of the lecture/discussion. It's certainly at issue how successful I or my peers are at doing that. Formerly, homework was done, well, at home. In the new scheme, lecture takes place at home and problems are solved in class. That's an oversimplification perhaps, but it leads me to the issue I want to raise.

I have heretofore seen one of my roles in the pedagogical process as catalyzing the acquisition of the primary concepts of the course. In fact, I have somewhat discouraged students from reading material before class, generally thinking I can cover it better or more effectively in class. Likewise, I have valued the role of interaction during lecture as a way of customizing the material and making it easier to absorb.

My sense is that the best thing is an interactive lecture/discussion along with student-driven problem solving. But that's probably beyond a 3-unit course.

What are your thoughts about this?

Another thing we're trying is "studio" format for some aspects of a course, where students work in groups and we watch how they approach problems and offer critique and advice. It's a model used successfully in the Architecture School, and we've been watching what they do and trying to adapt it to what we do. I'm doing my first studio session tomorrow for CSE431.

It's interesting that the conversation about candidates and their positions has shifted from Iraq and the "war" to domestic problems with our economy. We've moved from a topic where there were clear differences between the parties as to what should be done (should we stay or should we go?) to a topic where it's almost universally held that something should be done, and the parties are mostly in agreement about what they will do.

The Republicans should be breathing a sigh of relief.

However, except for NPR, I don't hear much mention in the media about any connection between the Iraq activities and our domestic economic problems. At $177M per day, one can't help but wonder to what better use such funds could be put?

Also, except for NPR, I don't hear anybody asking from where the money will come to pay for the tax rebates that both sides of the Aisle seem to think will jump start the economy. Some senator was interviewed about this today on NPR and he told a fine story about the good that the rebate will do. When the interviewer asked where the money would come from, the senator just about fell apart. It's going to be borrowed, he finally said.

Borrowed? From where? We owe China trillions already. The interviewer even asked if the government was just going to print all that money and send it out as rebates. Again, the senator fell apart, saying that Bush's plan and his amendments all amounted to the same kind of thing....but he couldn't really articulate what kind of thing that was.

There is a link between spending in Iraq and insufficient funds at home. There should be some basis for generating tax refunds, in terms of spending cuts or revenue to pay for it.

We are again being sold a bill of good and being steered from the conversation that would have taken place to a conversation where only the public can lose. Brilliant, really.

I went to the Blues game last night, and decided to lower my carbon footprint and blood pressure by taking Metro Link. No problem getting to the game.

But on the way home, I waited on the platform while 2 trains in a row came by headed for the airport. I needed a train heading to Shrewsbury.

When the 2nd train arrived, the platform manager told us we should use that train and get off at Forest Park to wait for the Shrewsbury train. This made no sense to me since it's just one set of tracks, and the Shrewsbury train would have to pass through the station where we were, but we did it anyway.

Waiting at Forest Park, another train for the airport came through. I asked the platform metro policeperson if there would be any Shrewsbury trains that night, and he had me use the platform phone to talk with the dispatcher. By now there were many people waiting.

I called the dispatcher, and she told me that the string of 3 trains for the same destination was normal and was on the schedule. But I looked on the web at the schedule, and she was wrong: the trains are supposed to alternate destinations on the schedule.

The trip home took nearly an hour, and I have entirely new thoughts about using Metro Link. I've used it 3 times to go to the Blues game. The first time, during an ice/snow storm, the trains shut down going home and we had to wait nearly 2 hours for a taxi to take us home. The 2nd time was fine, and then there was last night.

You would think, with Highway 40 shut down in spots, and a Blues game going on, the Metro Link people would make sure trains are going where they should.

Betsy: Aaron didn't make it to lunch because he got a flat.

Melanie: How did he get a flat?

Me: He's a saxophone player, so he probably ran over something sharp to get a flat. Accidentals will happen you know.

Melanie: That's not natural.

Me: I wonder if he told the whole staff?

I was talking with one of my CSE531 students today who is involved in a large software project at his job. He agreed with me that most projects of any reasonable side are underestimated in terms of how much time it will take to complete them.

One would think that errors in estimation would balance out in a long-term project, so that project lateness might fit a Gaussian curve with a peak at 0 for on-time projects. Not so. A site of megaprojects cites underestimation of completion time as pandemic. Our own beloved Metrolink project went over budget, by a paltry $126M. Besides being late and over budget, the consequences of underestimation included law suits (which Metro lost) costing even more $$.

We don't underestimate everything. When bridges are built, they are usually built to overestimate the load they will experience. We can err on the side of safety if we try.

So I proposed to this student that the reason big projects are underestimated is that if the true estimate were known, people would balk at the expense and give up on the project at the start. If a project is 90% completed and needs 100% more funds to finish, people are more likely to capitulate and spend what is needed to finish up the project.

So this student told me that when he estimates the time to do a task, his management cuts it in half to keep cost down. Then the project ends up going twice as long as budgeted, and management starts yelling. I suggested that he try an estimate of 4x, but he tried that, and management cut it down by a factor of 4 to help the project come in under budget.

Can we say codependent? Sure we can.

When will the real world get real enough to do a better job of estimation?

For at least the past 16 years -- since my arrival in St. Louis -- the intersection of Warson and Ladue roads has needed a traffic light to facilitate traffic during rush hour. Much of the congestion, particularly in the afternoon, is due to the school at that intersection, MICDS (Mary Institute Country Day School, a private school). It has been my understanding as communicated from my neighbors that Ladue (the small municipality where we live in St. Louis county) has been saying all these years that MICDS should pay for the traffic light, and MICDS wants Ladue to pay for it.

I don't often need to traverse that intersection, but whenever I do at rush hour, I am struck by the phenomenal waste of time just because the Right Thing can't be done. I've thought about how I should contact City Hall, organize a rally, and write a folk song to get the traffic light installed. But I never did anything of the sort.

And lo, a miracle! Because the highway construction project on Highway 40 (that's I-64 to you nonlocal people) will cause said highway to be shut down for a long period of time, the project included funds to put traffic lights on the East-West arteries to facilitate traffic flow during construction.

As a result, traffic lights have sprouted up along Clayton Road, and further West on Ladue Road at Graeser. Those lights are working nicely in spite of no real need for them yet.

A week or two ago, construction began on the traffic light at the intersection featured in this article. Of course, it is not working yet, but seeing the poles and signal lights erected is enough to give me hope.

In the midst of Chanukah, which is seasonally oriented at Winter solstice and thematically associated with (re)dedication, I am thankful for the increased light, particularly traffic lights, and I seek to rededicate myself to worthy causes. And while there are surely causes more worthy than alleviating traffic congestion, charity begins at (near) home.

Here's wishing you also the benefits of increased light.

A former student of mine sent me this. This could start a new movement to unsecure networks.