Friday, December 28, 2007

Merry Christmas!

A bit belated, but not much time to blog when you are having fun!

We have been in The Great White North (literally and figuratively) since Christmas Eve, enjoying time with The Thomas and The Parents, among others.

We got a late start on the trip because Mrs. Pion had been seriously under the weather, but a real doctor and some rest took care of that. Fortunately, we had built in a lot of slack in our schedule so we really did not miss anything. Even more fortunately, the weather was even better for our drive north than it would have been on our original plan.

Even better than that, it was all white when we got here!

It is not Christmas in the Pion family without food. Suffice it to say that we arrived at 3 pm, Parents arrived by 4:30 pm (barely enough time for us to unpack the car), and the ham dinner was served by 6 pm. SisInLaw had knocked herself out as usual, with a choice of 4 pies (chocolate cream, pecan, banana cream, and lemon meringue) and banana pudding, all home made, along with Christmas cookies and ice cream. I settled for a half slice of pecan and a half slice of chocolate cream, with ice cream on the side.

Santa arrived while we slept. (The great bulk of the gifts exchanged within The Brother's family are piled around the tree by Santa. They don't accumulate them under the tree during the weeks - or days- before Christmas like we do.) Oddly, Mrs Pion and I were well rested during our trip, so we were first to get up and have breakfast, but resisted the temptation to unwrap and rewrap the gifts. The others were all worn out from getting ready for us to visit.

We were all well remembered. The gift that keeps on giving, a 1000 piece jigsaw puzzle, has kept me and their kids entertained for the last few days.

Christmas dinner, a huge turkey and trimmings, was as good or better than the night before. Although I could complain about the lack of sage in the stuffing, I really can't because Mom can't enjoy spicy food like some of us can. Besides, the stuffing was highlighted with the addition of cherries, which add their own special flavor.

Boxing Day was spent on the road, to visit Mrs. Pion's big brother in the even greater, whiter, north woods. Close to Hemingway country, if you know where I mean. We had a special delivery to make: part of our grapefruit harvest. These came from a tree that his wife had started from a grapefruit seed, and gave to us after we had moved south. It rather amazingly has survived enough winters to bear fruit. Great visit, and a beautiful drive through the north country. Once again we were favored by good weather and clear roads.

Finally, we worked in a day for a family dinner at my Parents new home, a townhouse that is part of a wonderful retirement community. I'll have to blog about being Homeless (for the first time in my life, I don't have a bedroom or even a bed in my parents home) some other time. For now, I'll close by being thankful for yet another pleasant evening with family, including a brother who should be immensely proud of how his kids are turning out.

Hope you all had a great holiday as well.

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Thursday, December 20, 2007

Efficient grading (physics and math)

This will have to be the short version, since I have to do some real work tonight.

My experience is with quantitative subjects like physics and math, but since it seems to have some value for stuff that requires reading (like lab reports), it can probably be adapted for other subject areas. Details below the fold.

The starting point is that you only grade one problem (or even sub-problem or portion of a report) at a time. That was a given when grading 750 final exams in one day, because each person does one problem while piles of papers get pushed around a big conference room table, but it is also how I grade exams solo.

Here I will assume you are grading the entire exam of 40 or 50 papers yourself, maybe 400 distinct problem solutions. There are some differences when you are only going to grade one problem on 750 exams, so I will summarize those at the end.

My exams all have a cover page for the total, version, etc, so the first step is to turn the page to the first problem to be graded and invert the stack so the first papers turned in are at the top. If not, just set it up for the first problem, which might not be problem 1 on the test. If there are multiple versions, set them up so you are grading the "same" problem on all versions. This is key.

I always start grading with an 'easy' problem. I never start with one that might have N-8 distinct wrong answers. Too depressing, and it defeats the key step.

Sort the exams by answer. That is, make one pass through the tests looking only at the bottom line, the answer and its units. Completely correct answers go in one pile, ones with minor numerical variations or missing units go in another, and ones with wrong answers go in a third. Keep exams with the same wrong answer together.

Reassemble into one big stack and work through them starting at the top, or in the middle if your rubric has a key intermediate result or formula identified for that problem. Just because the answer is right does not mean the solution is right! This goes quickly for 'simple' problems, but requires a bit of care for ones where there are ways for two wrongs to make it right. It does take some experience to know which problems are likely to have 'magic' algebra steps where negative signs mysteriously change as needed, for example.

[Side remark: It is crucial that the solution be checked along with the answer. Many of the algebra weaknesses I see could only have made it into physics and calculus because an algebra or trig teacher did not check that they took the square root of a negative number and just made it into the correct real answer. I don't want that kid designing a bridge I have to drive over!]

There are two advantages here. One, the exams that deserve the same partial credit are next to each other. I may make a note on my key to say how certain errors are dealt with just for future reference, but I rarely have to consult them or look back to see how some weird thing got graded. Two, the exams are usually in the optimal order when it comes time to grade the next problem.

Next problem, same process. However, now the odds are that you have correct answers already at the top. The fact that you see a lot of correct exams before getting to the dregs is great for grader morale, which improves my efficiency. You do have to be super careful not to overlook errors on good papers or be too tough on the bottom. When a "top" paper has an error, it goes to the very bottom and when a "bottom" paper has the right answer, it goes to the very top. Sometimes I cut the deck, as it were, just to be sure I am fair (particularly for a long exam like a final).

The key is that you do not look through the entire solution for every paper, just the ones where you need to figure out what they did. Even then, you often get the efficiency of knowing that four papers all made the same kind of error in step 3 or 4 of the solution. You only have to figure it out once. After that, your eyes go directly to the error, flag it, and move on.

Handling each exam twice is more than made up for by less time spent on each one. I am also less likely to overlook an error in units or significant figures if I check that detail in my first pass. That means I also save time by not having to go back and look at an exam that was already graded.

Changes for Really Big Classes:

We would pre-grade a few dozen exams, picking out specific students from our own sections if that was practical. That would set up the rubric and give us some idea of what we had to watch for, but we also kept a sheet of paper with wrong answers listed along with the partial credit it got (and the reason why) when new ones showed up. This makes up for not being able to sort the exams. The basic idea was still the same: work from bottom to middle to top (or bottom to top to middle) of the solution to check the answer, the algebraic process used, and the physics.

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Profgrrrl has a thread about how people compute their grades. I commented there, but thought I would elaborate here.

Like her, I use a spreadsheet ... but I use Quattro Pro to do the grade computation rather than M$ XL. I also use an old fashioned grade book, which stays in my briefcase. The grade book is only for transient records (I don't carry a computer around with me), answering student questions, flagging something that will need correction (whether late assignments or a grading error) and a bit of permanence should something crash.

There was a gap where I only did research, so I can't tie my transition from paper to a spreadsheet to any specific change in the available tools. My history doing grades is quite a long one:

  • Undergrad TA: All grades were calculated by hand, since calculators did not exist at the time and slide rules can't do addition. Exams and quiz scores were added up by hand, as were final averages. Some habits carry over from those times. I still keep a grade book in that style, and I still transfer the sub-total for each page to the front of the exam for final computing. That was when I was teaching math, and lots of math faculty still do it this way.
  • Grad Student: I had a calculator, so most serious arithmetic was done that way. Exam scores were usually added up in my head, because I could do it faster than a calculator. Never bothered to write a grading program in Fortran because they already had one (or was it in COBOL?) for the really big lecture classes that did not have any homework grade.
  • Side comment: That was where I was taught how to grade exams really efficiently. It was only recently that I learned this had a name: rubric. But it is more than that, it is an assembly-line-like process. I may blog about it if asked. Once you can grade one problem on 750 exams, accurately and efficiently, you can grade anything.
  • Research Faculty: I taught some classes while on a full-time appointment that allowed that in addition to doing research. That was where I developed a grading spreadsheet in Quattro Pro that I still use today. It had three sheets (summary, homework, exams) just like mine does today.
  • CC Faculty: Nothing much changed, so nothing much changed. Once you have a PC, there is not much else to do but put it on your phone. But the security issues if that phone got lost? Priceless.
My comment on Profgrrrrl's blog about not having to remember how to do formulas comes from this experience. I have not built a totally new spreadsheet since the first one, maybe 15 years ago. I've only had to make minor adjustments as my grading formula changes.

So my grading process has two stages. I first enter grades into the grade book, even if I am home where the computer version lives. They go in the grade book with the same pen I have in my hand, and are easily entered in random order. (I alphabetize exams before handing them back, but not labs or homework, so that is an important detail. I can see an entire class in my grade book, but can't see the entire list on a computer screen.) I then copy them into the computer, now alphabetically, and cross check if it is important, like an exam.

At the end of the year, I "print" the final spreadsheet info to pdf and keep it on two different computers (home and work) and in two separate hard-copy files (one with the final exams at work, the other is the actual gradebook).

I can't imagine not using a spreadsheet. Besides the advantage of getting the numeric grades as soon as the final exam numbers go into the computer, it is also easy to generate midterm and other grades for the students. I don't use Bb for this because I use a different course management system and our college does not automate grade transfer from Bb to our on-line grade entry system. I'd have to transfer too much info from one place to another to make that work.

A big part of the grade comes from HW managed through a non-proprietary course management system. I print its gradebook for each block of HW when I give an exam, and use that for two things. One, it is a hard record of those grades that get transferred into my grade book and computer, and two, it is a way to keep records on possible correlations between specific exam questions and HW performance on related problems. Are they learning? I've learned that it matters more whether they tried the problem seriously than if they got it right. Kids who get it right by using their book, notes, or (more likely) advice from friends might not do as well as kids who got it wrong but figured out what they were doing wrong after they saw the answer. In fact, I have evidence that this is exactly what happens.

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Monday, December 17, 2007

Good, Bad, and Ugly

Well, the semester is over so it is time to look back. Unlike some of the bloggers I read regularly, the end of the semester did not bring out the cloying annoying students that some had to deal with.

The Good:

My students. Not because I had a high pass rate, because I didn't. Last fall was outstanding while this fall was just above average. Because the ones who passed did a really good job. This was a class that was going to be either A or F. And since the F students will not be in my 2nd semester class, it looks like spring with this group is going to be a lot of fun.

But mainly because I just did not have any of the annoying ones that Profgrrrrl and RH were blogging about. But it was not that simple.

More of the Good:

Facilitating instead of doing. I tend to just do it. The sage on the stage. But a few weeks ago I managed to pay attention to a side comment at an engineering lunch meeting and put it to good use. A former student is part of a team building something for a national engineering competition. The guy at my table mentioned that he had been in the same competition 10 or 15 years ago. After lunch was over I introduced one to the other and watch an electric moment. You don't actually have to do the teaching to be a teacher.

Starting an ed research collaboration with an old friend from grad school. I think this is going to be really interesting.

The semester started and ended on a high note. During the pre-semester faculty meeting, my Dean closed by reading an e-mail he had gotten over the summer. He said he did not usually do this (he doesn't), which is a good thing. I could barely handle that one instance. After the first sentence I knew who wrote it, and so did the chemistry prof sitting next to me. This was a returning student, mid 30s career woman, going back to school to become an engineer. There were six of us who changed her life. I did not mind that I was an afterthought at the end, because it was the other five who got her to my classroom prepared to succeed. And just yesterday I got a note forwarded to me by one of the math faculty, a note thanking him for his clarity in teaching vector calculus and mentioning my efforts (the previous spring) as well. Most of the time they just walk in the door in August and walk out in December and you never really know whether you had an impact.

Yeah, and there was the Iraq war vet I ran into in the supermarket just last week, who is showing that an average CC student who put an emphasis on learning can kick butt when put up against those kids who started at the university. He even has one company ready to hire him after just on summer as an intern. And there was another vet, an ex-Marine (as if there is such a thing) from the inner city slums of a northeastern city who stopped by in August to tell me he had graduated and was off to take a job in Washington DC. Every one of those stories helps dispel the myth that CC students are inferior and helps the next group do even better.

Oh, yeah, and profgrrrrl is well on her way to earning tenure.

The Bad:

Too many meetings. I knew serving on a major (actually, the most major) college committee would be a strain, but you never know for sure until it happens. To those who know, there is nothing more that needs to be said.

The kid who had more persistence than sense of reality. The odds of passing the course with a great final exam are not good if you averaged 65 on the hour exams. He did not even make 50% on the final. I suspect, from what I saw in the lab, that he confused understanding how to do a HW problem with getting it right after someone told him how to do it. That might help on an hour exam, but it won't work on the final and he proved it. But maybe he will be in the 'good' category after next semester. I have seen that happen, and maybe he needed to fail the final exam to really learn that his approach will not work.

The Really Ugly:

One of my lab TAs did not turn in his grades on time. No trouble with the students, but trouble with their teachers! That was a completely new experience for me. Sigh. I suspect graders block or terminal procrastination. I saw some hints of trouble but never suspected it would turn out this badly. The worst thing is that he is a really good teacher in the lab. I see a stressful spring.

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Tuesday, December 11, 2007

Grading Playlist

Pretty good progress grading so far. Got all of my final lab reports and lab exams graded so they could be returned at the final exam for the lecture course, and wrapped up the final exam for one class (the small one). That took me through

  • Cream: Strange Brew
  • Beach Boys: Made in the USA
  • Heart (the debut album)
  • Jethro Tull Original Masters
  • Led Zeppelin
  • Beatles: With the Beatles
which carried me through on-line grade entry for those three classes.

On tap is my larger class, where I still have to "take" the exam and write out the grading key. That will probably look like
  • The Beatles: Love (to work the exam)
  • Led Zeppelin (reprised due to recent concert)
  • Jimi Hendrix: The Ultimate Experience
  • Les Negresses Vertes: Mlah
  • Temptations: 17 Greatest Hits
If that does not do it, I'll add an update.

PS - Gotta love the tune "Zobi La Mouche" from the debut album of Les Negresses Vertes, a French band whose use of folk instruments (including the accordion) produces a sound that reminds me of Cajun music. Great energy for grading. The only problem with it showed up when I asked a young french post-doc to translate the lyrics. She was too embarrassed to tell me more than what the title meant.

Addendum: I did have to add a few disks to finish that last exam. Since I knew that I needed to think hard about the N-8 distinct wrong answers to a problem some of them found particularly hard, then slam through the last few problems and add them up, I went with
  • Beatles: Rubber Soul
  • Miles Davis: Relaxin'
  • Yes: Fragile
  • Beethoven: 9th Symphony (Dresden Philharmonic with the Berlin and Leipzig Radio Choruses)
That did it.

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Holiday Music

Time to destroy those childhood mythologies: Check out this remix of Alvin and the Chipmunks that has been slowed down so you can hear the original vocals. From M-1.US.

On that thought, need some Mashups with your mashed potatoes?

Check out SantasticIII in 3-D.

If you like that, go back a few years to SantasticII: Clausome! (2006) and Santastic: Holiday Boots 4 Your Stockings (2005).

Motivated by an article by Dean Dad complaining about lousy christmas music. He's never heard "Dreidel All The Way".

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Saturday, December 1, 2007

FSM at a national meeting

There is an amusing report in a blog about a session devoted to the subversive value of a parody like the Church of the Flying Spaghetti Monster. If you have never heard of it, FSM was invented in much the way Intelligent Design was invented, but for the opposite reason.

The FSM is quite popular around our department, since some of the biology folks regularly encounter kids who have been taught bogus biology in Sunday School. We are now seeing it spread to geology and oceanography (somehow global warming is against the bible) as well as physics (radioactive decay and entropy).

One office has a "What Would FSM Do?" sign on the door, and another of my colleagues went so far as to make up a Christmas decoration featuring a stylized FSM made of LEDs. The latter is quite pretty.

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