Friday, November 23, 2007

Why top-down text adoptions are wrong #417

OK, the 417 might be an exaggeration, but there are many, many reasons that adopting one physics textbook title for use throughout a multi-school district is wrong.

I've listed the others in a "manifesto," but a new one struck me as I was examining the lab manual CD for Holt's Physics by Serway & Faughn. Many of the lab activities in that resource are Calculator-Based Laboratory (CBL) activities.

I'm not a big fan of CBL. For "tech-labs," I prefer the use of laptop computers. Small gizmos like calculators or single-user sensor monitors isolate students during lab work. One laptop shared by a group acts as a focal point and brings students together.

Still though, many teachers do like the CBLs. And teachers who like CBLs might lean toward adopting the Holt text so as to acquire the CBL-rich lab resource. And they should be allowed to do so.

Other teachers within the same district (like me) might be less keen on the CBLs and might be less interested in the Holt textbook. They might prefer a competing title for a variety of reasons.

Should they be forced to adopt a book they don't like and lab resources they won't use?

Better to let each school site decide which title meets the needs of its own program. That's always the best plan, actually.

Wednesday, November 14, 2007

PftM2: "Mr. Physics Teacher, tear down this wall!"

In the old days, you had to pass chemistry and Algebra 2 before signing up for physics. Those prerequisites considerably narrowed the potential population of physics students. And the big secret? It turns out you can teach a perfectly good physics class to students who have not passed chemistry or Algebra 2. For a first-year physics course, there's no reason for either of those prerequisites. Let them go!

Will you end up with some "less-qualified" students in your classes? Yes. But accept the challenge and work your craft. You are fortunate enough to teach physics, so teach physics! (And rejoice!)

I don't encourage Honors Physics. I like a "big tent" in my Physics 1 course. Heterogeniety rules! I strongly recommend heterogeneous lab groups. Email me for details on how to make that happen.

Make it possible for all students to succeed. Not all students will succeed, mind you. You cannot have complete control over that. Without the barricades in place, you'll have students who don't intend to be scientists or engineers. And that's OK. Working your craft as a physics teacher means you'll have to guide those literature, arts, and athletic types to success in your class. They won't all follow, but success has to be accessable.

A wise vice principal once told me, "Not all baby sea turtles make it to the ocean." But let students choose their path in your course. Lay out the options. Make them "doable," and let students decide with their actions. You might worry this will water down the rigor of your course. I can say that I get some really bright students at my school and if even the smartest among them was ever bored in my first-year class or felt unchallenged, they never told me.

What am I suggesting, specifically?

Don't put all the weight of the grade on test and/or exam scores. Allow for the fact that some of the ideas of physics require time to settle in. Let students review tests after the fact. (I use a technique called "Test Correction Journal." Topic for another post some day.) Then give them more questions of "old" material on future tests. In EdSpeak, that's called "spiraling." Whatever it's called, it allows time for material to settle, and engenders the idea that "old" material is still important. As the semester progresses, unit tests look more and more like mini-final exams. And that's OK.

Don't grade homework for correctness. Credit for homework is tricky. Students want it and teachers don't want to give it. My analogy is to ask student athletes about practice. "Before the match on game day," I ask, "how many points do they put on the scoreboard in recognition of the practice you did all week?" There are clever ways to encourage the completion of homework. I use a technique called "The System" which is a general method to encourage good academic behaviors and discourage the bad.

Don't forget to have some fun from time to time. Throw eggs. Do groovy demos. Show Roadrunner cartoons. Laugh. You're teaching the grooviest subject on campus; there's gotta be some fun in there somewhere.

The biggest challenge for any physics teacher is simply to remember how hard the material was the first time. A tall order, especially for those of us who have had significant coursework and years of experience. Doubly challenging if physics came easy to you. (Happily, I was never "cursed" in that way.)

If you've got Algebra 2 and/or chemistry barriers in front of your physics course, you're keeping a lot of good students out of your course. And denying them an excellent high school physics experience. Don't do it!

Momentum lab sequence of happiness

In the canon of introductory physics experiments, the conservation of momentum lab is a classic. High school and college instructors have used a variety of techniques to bring conservation of momentum to students through the years.

I recall using skate-wheel dynamics carts and ticker-tape timers to complete the lab. Dragging paper tails from three-wheel carts had limitations, but it got the job done. By the time this lab was done, students had already learned how to analyze the purple-dotted ticker-tapes.

When I implemented the lab at Rio, I used slick Pasco carts and tracks and photogate timers. Details required attention. Students had to know how to use the photogates, timers, and cart flags to get initial and final speeds of the carts. And the timings had to be done close to the event to keep friction from interfering with the results.

As I recall, my early attempts were to do conservation of momentum as an inquiry activity. I later settled on more of a verification approach. It seemed that no matter what method you used, there were always abundant details of the measurement technology.

That hasn't changed. But now I use motion sensors instead of photogates or ticker-tapes. Nothing needs to be added to the carts. And measurements of speed can be made within a fraction of a second before and after the collision or explosion. Students still need practice and guidance to understand and use the speed measurement technology. But this approach strikes me as the most transparent version I've ever done.

The sequence I've written and implemented also involves the use of a spreadsheet. In one activity, students plug numbers into a spreadsheet that does all the calculations for them. In the the final activity, students must enter their own equations into the cells.

It's a nice sequence on a number of levels. But it does take some time. Six class periods to learn the technology, implement it in inelastic collisions, and implement it in explosions. When lab groups finish one activity, they move on to the next one. Some groups may finish early, but others will need every minute. My early-finishers got to compete for the high score on PhET's Lunar Lander. (One student scored an "out-of-this-world" 150!)

Anyway, here's the sequence.

1. Datastudious. This guides students through the the use of Pasco's DataStudio for the purpose of monitoring motion on the track.

2. Crash and Stick: Inelatic Collisions. How to use the carts to create an inelastic collision. How to use motion sensors and DataStudio to monitor an inelastic collision. And how to enter the data into a spreadsheet that then processes and interprets the results.
Inelastic Collisions Spreadsheet (Coming Soon!)

I know what you're thinking: students should have to program the spreadsheet themselves--this is simply a low-level, "cookbook" lab. Patience... we'll get there. One step at a time.

3. Such Sweet Sorrow: Explosions. Use motion sensors and DataStudio to monitor explosions. This time, you need two motion sensors. And this time, students must program Excel themselves. (See; I told you we'd get there.)

Tuesday, November 13, 2007

Physics for the Masses (PftM)

High school physics is changing. In many ways, for the better.

In the old days, physics was a class reserved for the 20 smartest boys at a given high school. A rigorous, trig-based textbook, such as PSSC Physics, was used. All lab activities were quantitative, and the use of higher-level algebra and trigonometry was expected. It mirrored the introductory, non-calculus college physics course.

And very few high school graduates ever took the course. PSSC's focus on rigor was a response to Sputnik. America was being beat by the Soviet Union in the Space Race. But the drive to put us on the moon closed the door on most students. And it's not like physics was a class for the masses in the pre-Sputnik years.

Since the 1960s, things have changed. Paul Hewitt's Conceptual Physics gained wider acceptance with each passing year. Physics enrollments seemed to rise step with the rising adoptions of Hewitt's text.

A nationwide, "grass roots," Physics First movement has been afoot for over twenty years. Where it's taken hold, all high school freshmen take physics before moving on to chemistry and finally biology. But that movement has been effectively banned from California public schools, so we'll set that topic aside for now.

With California's push to enroll all high school freshmen, sophomores, and seniors into standards-based science courses, there is some additional pressure to get students into a physics class.

I'm all for it. I think every college-bound high school student should take physics. I'll add posts from time to time with "PftM" (Physics for the Masses) in the title. They'll include some ideas on how to increase physics enrollment. You probably have better ideas than I do. That's what the comments are for!

Saturday, November 10, 2007

The end of concertgoing

I see a lot of live concerts every year. Hey, everyone's got a hobby; seeing favorite musicians practice their craft is one of mine.

If I ever stop seeing concerts, it won't be because there aren't shows I'd like to see.

It will be because I can no longer take sharing the space with thousands of other people, many of whom don't know how to attend a concert. Going to see a big performance of live music is not rocket science, mind you. But it's far too complex for many to grasp.

More and more people seem to want to pay $100 to sit with someone they know and gab for 2+ hours while music plays around them. Of course the music is so darned loud at these shows that they have to yell at one another to keep the conversation going, They are dumbfounded by the rude people around them who stare and shush.

My first recollection of this being a significant problem was at Lilith Fair. I thought perhaps it was a "girl-thing." It seemed I was surrounded by women who weren't there to see or hear The Indigo Girls, Natalie Merchant, Sarah McLachlan, etc. They were there to sit and chat. Apparently Lilith Fair was the only time/place they could engage in such behavior, so they had to make the most of it.

But the two loud, chatty 20-something men next to me at James Taylor the other night put the lie to that theory. And they weren't the worst offenders in the audience that night.

No, the hands-down winner of the Audience Idiot award was the woman who paid her hundred dollars for the right to tell James Taylor to "Shut up and sing!" Taylor was introducing "Line 'em Up" with his typical wandering back-story. Several seconds into the story, idiot-woman decided she'd had enough. Though she was booed by audience members blessed with more than two neurons to rub together, Taylor stopped the story and launched into the song.

That was probably his only winning option. He later worked the line into his ad-libbed lyrics to "Steamroller Blues" to the delight of the otherwise mortified audience. Nevertheless, I'll go out on a limb and say JT will never burden Sacramento with his wandering stories or a live concert again.

It was also a Sacramento audience at the Genesis show who seemed transfixed by the cacophonous "Mama" (featuring Phil Collins' evil laugh as "lyrics") but headed for the bathrooms and concessions during "Ripples." No accounting for taste in this town! I could be wrong; perhaps "Mama" has an undocumented diuretic effect.

I don't recall the last time I attended a concert of any type anywhere in which the artist was allowed to fill the space with a quiet moment. No, any reduction of decibels from the stage is apparently a universally-understood invitation for screams and shouts from the audience. Everybody knows that! How do I not get that?

I don't see the trend reversing; I don't see concertgoers becoming more civilized in the future. Some people thought that the terrorist attacks of 9/11 had a sobering effect on the population. Casual Fridays were gone and everything was more serious.

The effect on concertgoers? More than three years after 9/11, I was at a big show in Reno. The artist was British pop legend Elton John. There were certainly audience members who brought to mind the Johnny Cash line, "I shot a man in Reno just to watch him die." They were composing flash photos of themselves at the show with the band performing in their background. But the crowning moment came in the audience's call for an encore. For reasons that elude me to this day, a chant of "U-S-A! U-S-A!" rose through the rafters.

Maybe they just need to stop selling booze at these shows.

Sunday, November 04, 2007

Tales of textbook adoptions, part 2

This past Thursday, a group of SJUSD physics teachers met at a "re-purposed" former elementary school. The agenda: publisher presentations on textbook programs we expressed an interest in at our previous meeting.

My first textbook adoption happened when I was still wet behind the ears in 1987-88. I've been through two more before this one. This was my first time being pitched by publisher reps at a district-organized meeting.

The first, second, and third adoption cycles involved a few meetings of physics teachers throughout the year, culminating with selections of titles. In 1988 and 1994, each teacher simply identified the title of his or her choice and the books were ordered for distribution in the fall. In 2001 a new directive came down from the district: choose one title for physics and a second title for for AP Physics. The physics teachers balked, fought, argued, and won the case for selecting different titles at different schools.

The top-down, "one size fits all" directive from the district is back again (perhaps stronger than ever), and again the teachers are balking.

But there's another difference between the 1988 adoption and the 2007 adoption. In 1988 I was loaded down with a small library of complimentary copies of many, many titles. Back in those days, there were many publishers. Not any more. In this weeks presentation, we heard from Holt and Prentice Hall. Although Glencoe/McGraw Hill has a title, no one was interested in piloting it. There was notable dissatisfaction with that title throughout the district.

Holt had long published the venerable text, Modern Physics. More recently they retooled with a title authored by veteran authors, Ray Serway and Jerry Faughn. Though it got off to a rough start, holt's Physics is now a sophisticated, multi-faceted, resource-rich textbook. At first glance, I have no reason to think it's anything but a good, solid, high school physics textbook.

I'm obviously a big fan of Paul Hewitt's Conceptual Physics. I have used it since I started teaching. Other programs may have a more impressive fleet of ancillaries, but Hewitt's text will always have something they cannot match:

A student who doesn't know physics can read Conceptual Physics and learn physics from it.

You might expect that that's the case with any textbook. It is not. I have yet to see a text whose narrative matches Hewitt's in its ability to explain physics to a student who is unfamiliar with the subject. Most authors have long held a command of physics and simply cannot remember what it was like when they didn't "get it." Hewitt followed an unconventional path to his position as physics instructor and textbook author. And it shows. He seems to remember not getting it and thus speaks effectively to students who are learning the material for the first time.

Nevertheless, Prentice Hall has worked to make sure the armada of Conceptual Physics ancillaries can do battle with those offered by the competition.

At the end of the meeting, we signed up for piloting duties. Several signed on to pilot Holt Physics, several signed on to pilot Conceptual Physics. We also went in several directions for an AP text. I'm hoping to see the latest Serway & Faughn College Physics (7e); others like Douglas Giancoli's Physics Principles with Applications (6e).

It would appear that at worst, we would want two titles for physics and two for AP. It remains to be seen if the district will let us have our way or force us to fight amongst ourselves over which single title for physics and which single title for AP should be adopted district wide.

Which color laser multifunction printer?

Consumer color laser printing was a mature technology when I bought an HP 2500 in 2003. The printer itself was (as I recall) about $500. I paid extra to get an actual paper tray. And when the toner cartridges ran out, replacing them nearly matched the original cost of the printer.

The $175 imaging drum recently expired, and the $400 worth of toner was down to half capacity. To keep the HP going was going to take about $600 to keep going another couple of years. So I started looking for a replacement. I do like color laser printing. And now there are multifunction machines that will print, fax, copy and scan--built around color laser printers. My interest was piqued!

Since I had let four years pass since the 2500 came out, I was ready to be wowwed by the newer, better, and less expensive models that would surely be out there. For a nice multifunction, I'd be willing to part with up to $800.

Strolling through the local big-box office supply stores, I came upon fewer choices than I anticipated. No shortage of multifunctions, but most are built around inkjet printers. A few are built around monochrome laser printers. Just a handful are built around color lasers.

Canon? I own a top-shelf Canon photo inkjet, a Canon digicam, and a Canon digital SLR. I like Canon. They have an ImageClass color laser multifunction. But they decided not to make it Mac-compatible. I might understand that in 1987, but not in 2007.

Hewlett Packard? As mentioned, I have an HP color laser and do like the print quality. When "testing" the copying quality of the multifunctions at Office Depot, the HP 2840 outperformed the competition. Further research at C-net and Amazon revealed some downsides. Most reviewers seemed to hate the machine. The accompanying software was singled out for particular dislike. And the 2840 was born in 2005. HP has let this model wither in a continuing barrage of negative user reviews for two years.

Brother? The MFC-9440CN gets a lot of love in the online pro and user reviews. It came out just this past summer. The prints seem a bit waxy compared to the HP, but the quality is good. It's Mac-compatible. I was close to a purchase when I looked for the straight-through printing option.

Heavy card stock doesn't bend, so printers that guide paper through a circuitous printing path usually have a straight-through option. You feed the card stock in through a front flip-out tray and it emerges to a flip-out tray in the back.

The Brother has no such option. It can print paper no heavier than 43#. For a $700 printer, that was a deal-killer.

So for now, I'm ponying up for the imaging drum on the HP 2500. I'll be good for 1500 more pages on the toner set. By the time they run out, there may be a product out there I can get excited about. If not, I suppose I'll look for a deal on toner for the HP. That will buy me even more time.