Grading tends to be the biggest time consuming task for teachers. For those teachers who want students to complete lab write-ups that truly reflect discover and learning, providing feedback on labs can be an even more daunting task. This year I started using a system that has significantly sped up grading the mechanics of the lab, allowing me to spend more time on their analysis. I use address labels with seven check boxes to allow me to quickly look over a lab to see what parts are missing. Then I'm able to go in and make more detailed comments about the sections I want to focus on.

Lab grading label (return address size)

I use Modeling Instruction (this is an older site, AMTA will be launching an updated site in the next week or so) in my class, which focuses on analyzing data to develop models and reach conclusions. In most labs students plot data to look for trends, then develop the equation of the line/curve. As you can see above, my check list focuses on their data organization and plotting skills. Again, this frees me up to spend my time on their analysis and conclusions.

As I grade, I check off each item that I see completed, and can circle items the student hasn't included (e.g. those dreaded missing units). Then I peel off the label and stick in on their report. The label is only an abbreviation, and needs to be backed up with more detailed expectations for the check list items. I provide students with a longer "Lab grading guidelines" page that they can refer to. My latest version is shown below:

Copies of Word documents for both of these can be found here (both are .docx format):

• Address labels (30 labels on a standard 8.5x11" sheet).
• Lab grading guidelines.

Watch the following video, the try to answer the questions below it:

1. What is happening to the truck and the carts when the carts start following off the truck?
2. What causes the carts to fall off the truck?
3. While the truck is moving, the left row of carts doesn't fall off the truck. Can you explain why they don't?
4. At about 7:57:52, the truck stops moving and yet the carts keep falling out. Explain what is causing this.
5. When the truck is stopped, the left row of carts starts falling off the truck. Why do you think this happens?

Answers

No, the answers aren't here. You need to figure them out yourself. If you have tips or questions you want to share, you may add them below, but if you give away too much I'll delete them.

I've been using Modeling Instruction in my physics class for the past five years, and keep wondering how to handle the problem of students who miss the whiteboard sessions (where students share their results and we reach class conclusions). These sessions are critical for student growth, as this is where they are challenged to look for patterns in their data, reflecting on it and comparing it with other groups' results.

I have created a video PDF file that walks students through the process we would do as a class, which you can find here (PDF format, 3.9 MB). This is an animated PDF file, with voice-over as I write. You can move forward or backward using the navigator buttons, or click on any section of the document to jump to that place in the timeline.

This being my first such attempt at such a video, I would appreciate people's feedback.

A bit of background on my class graphing methodology

1. I don't 'linearize' data (a method where students graph p/t^2 to get a linear relationship).
2. I start with hand graphing constant velocity cars, then students use their calculators to conduct a linear regression on the data. They generally like the calculator option because it's so much faster than hand graphing. (All our students have TI calculators, so we use these instead of Excel--I have a handout that walks them through the process, you can download it here.
3. When we graph the data from the accelerating wheel on a ramp, students notice that the relationship is not linear (and they had predicted this from the pre-lab observations). At this point I introduce Quadratic Regression on their calculators, which presents them with y=ax^2+bx+c as the solution. They can determine that "c" is the initial position (plug in t = 0, and y=c), but they do not know what "a" and "b" represent. To solve for that, we move to creating a velocity/time graph:
4. Using the "Draw tangent" feature on their calculator, students draw velocities at increasing times (and notice that their velocity values are increasing, again, as they predicted).
5. Finally, with a velocity/time graph, we see a linear relationship, and can define the slope as acceleration and the y-intercept as the initial velocity.
6. Their final step is to determine what "a" and "b" on the position/time graph equation represent. You'll have to watch the video to get the answer (or, at least how we decide what you already know--that "a"= 0.5 acceleration and "b" = vi).
7. I use "p" for position in my equations and graphs. My students seem to have too big a problem with "x" for position, especially when we plot it on the "y" axis. (When we get to two-dimensional motion, I introduce "x" and "y" as positions.)

Hardware/software

I'm using a Livescribe Echo Smartpen and their Livescribe Desktop to generate the file. The pen allows you to write with normal ink and record all your keystrokes while simultaneously recording your voice. I don't like that it doesn't allow different colors, but it's fairly simple to use, and doesn't take a lot of post-production work (just save as PDF and the file is created). I also don't like that it appears to not allow landscape orientation, which would display much nicer on monitors/tablets/etc.

This hardware does not project live, so it's not something that lends itself to use during class, but it seems to give decent results in just a short amount of time outside of class. This video runs about 15 minutes, and it probably took me 30-45 minutes to create and publish.

There are multiple ways of saving/exporting the final products, and I selected PDF because it is so widely readable, regardless of Mac/Windows/iThing/etc.

At the AAPT Winter Conference, I attended a workshop on the Reformed Teaching Observation Protocol (RTOP) (emphasis on "reformed teaching" not "reformed protocol"). Below are my notes on that workshop. [This workshop runs 8:00-5:00 on Sunday, and I'm live blogging this so, if you're reading during this time, reload the page for the most up-t0-date content.]

Intro question: What does good physics learning look like?

My responses:

• Student engagement: hands on; notetaking; calculators/computers use; students doing things, not just passive
• Teacher engagement: focus on different groups of students; listening to students; circulating around the classroom; during lectures responding to students questions, circulating.

My partner and my negotiating of the top three:

1. Students making and recording observations.
2. Teacher circulating
3. Students solving problems.

Other groups' results (not complete):

• Vendor and customer haggling in a market-->discourse. [I really like this one] Teacher runs the market.
• Students engagement [I think this word is overused without a common definition]
• Student verbal reasoning
• Students designing experiments
• Students working on open ended questions
• Teachers guiding students through Socratic questions (although avoid "Socratic hammer" of step-by-step leading questions)
• "Avoid plug and chug" [I'm concerned with the oversimplification of this statement]
• We had a discussion of the role of lecturing--avoiding getting caught into the "All lecture is bad" dogma, but retaining that lecture should be minimized (a subjective term if there ever was one).
• We had another discussion about the role of writing. I felt that is was important that some student writing was going on in order for them to better retain the information; others felt that sometimes they didn't want their students worrying about taking notes, but rather just focus on the discussion. We addressed different learning modalities; in the end I think we could all agree with: Being prepared to write! (even if not all students write during the course of a period).
• PGA boards (post game analysis whiteboard)
• Body language/noise level of students.

Metaphors for teaching

• Market
• Jazz or blues
• Learning envelop
• Canals

Wrap up of morning introductory discussion

Our first video:

As a class we watched a ten-minute video of a college level lecture, taking notes and scoring it on our own. Over lunch, we met in threes and came to a consensus on our scoring on each of the 25 rubric items (ranking 0-5).

Our group got "stuck" over the question "The metaphor 'teacher as listener' was very characteristic of this classroom." We were trained to mark zero only if it was not observed. We discussed whether asking a question and responding to the answer qualified as 'teacher as listener.' I argued that if zero is only scored if it didn't appear, then listening did occur. Others felt that just because you ask a question, especially if there is only one right answer, that is not truly engaging in listening.

The workshop leaders emphasized that this is a constructivist tool, and the school that implements it needs to define what some of the terms mean to them. This seems like one of the strengths of this instrument: members of the institution need to agree on what are the goals of the institution.

Next video: A class for pre-service elementary teachers

Here we saw the difficulty of assessing teacher success when you're looking at a static video of one group during a group lab session (RTOP training uses videos to help attendees compare their results to others and notice what they are doing right/wrong). The instructor set it up well ("You need to show me your design of how the bulb will light up before you get the materials"), but we really couldn't see his interaction with the groups, so rating statements like "The teacher's questions triggered divergent modes of thinking" is difficult.

My conclusion: We need more professionally produced videos with multiple cameras/mics to let trainees see more of the classroom (anyone interested in volunteering to do this, I'm sure that Falconer and MacIsaac would be more than happy to have you do this--maybe I'll work on this in my "spare time").

On another point, sometimes we may not observe something directly, but the classroom culture may be such to lead the observer to conclude that the instructor clearly creates the environment. This can be either positive or negative, e.g. if you're observing group work, it may be real clear that the groups don't routinely do group work.

In talking about creating class culture of interaction/engagement, it occurred to me that this may be the difference between a "good" teacher and a "great" teacher. A "good" teacher may be able to get most classes engaged, and perhaps a "great" teacher can get (almost) all classes engaged.

 Third video: My class!

We were told on the course description that we could bring a video of ourselves to score. Last Wednesday/Thursday I had one of my students video me while introducing our acceleration lab (Unit 3 in Modeling mechanics). I had one ten minute shot that, while not the best audio/video, was a good representation of how I introduce the lab.

I thought I'd be doing the scoring myself, but Kathleen invited me to show it to everyone and have them score it. I braved my way to the front of the class and turned on my video for my classmates to score.

The leaders mentioned that the score would certainly be different if we had some video of the students conducting the lab, which is part of the problem of scoring video clips.

We're done!

I enjoyed the workshop, and look forward to talking to my department/administration about the RTOP instrument.

On a humorous note, I came up with the name for a best-practices teaching group: Community United for Learning-focused Teaching. (Write out the acronym.) Hey, I just Googled it and couldn't find it on any web page, so give me credit when you post it elsewhere

In transit lingo, "multi-modal" trips are those that use different modes to get to a destination. A common version is bike to bus/subway/rail, either taking the bike on the vehicle or locking it before one gets on. Today I had a wonderful trip that was multi-modal by accident.

The "out" trip was planned as multi-modal: I live in Berkeley and had a mid-day meeting in Redwood City. These cities are on opposites sides of the San Francisco Bay, and I decided that I would take two trains (BART subway and CalTrain diesel passenger/commute train) and ride the short distances between destinations and stations. I left home and rode five blocks to my local BART station, where I brought my bike on board and held it while sitting. Not too uncomfortable, not too crowded. When I arrived in SF, I got off at the first station (swiping my "Clipper" "smart-card"), then rode about eight blocks to the CalTrain station. I swiped my Clipper card while waiting, then when the train boarded I got on one of the two bike trains--these trains are specially equipped with bike rack space on the bottom level (the trains have two levels of seating). There were plenty of bungee cords at each bike rack,  and I bungeed my bike to the rack and chose a seat upstairs where I could keep an eye on my bike.

Getting off the train in Redwood City, I almost forgot to swipe my card, but there had been enough reminders on the train that I think it had been embedded in my brain and I remembered just as I was about to ride off. Good thing: They charge you the maximum amount when you "tag on" and give you a refund when you "tag off." I got $8 back

My ride was about eight blocks to my meeting. We had a good meeting (what would you expect from a bunch of physics educators?), but it went a bit longer than expected (what would you expect from a bunch of physics educators?). So I started about an hour later than I had planned.

My return trip was not planned as multi-modal. I planned on a 50 mile bike ride home.

Dirt road along levee in East Bay; Dumbarton Bridge on right in background.

Although my destination was north, I had to back-track a couple miles to make it to the Dumbarton Bridge (our only E/W bridge across the bay that has a bike lane). The bike lane is wide enough for two bikes to pass comfortably, and has a "Jersy barrier" between it and the traffic. A bit loud, but a  nice ride none the less.

On the other side of the bridge,  I ventured onto a bike route from Google Maps that I had not taken before. It turned out to be a dirt road, along a levee that separates the bay from the abandoned salt evaporation ponds (now nature conservancy areas). It was nice to be in the midst of our megalopolis yet still feel away from it all. I have a 7" Android tablet (Samsung Galaxy Tab) that has GPS and Google Maps, which helped me believe I was on the right course.

Three pelicans in the protected waters.

After about 30 miles, I had made it to Hayward and realized it was getting later than I wanted, and that I was more tired than I wanted. Luckily, the BART line runs up the East Bay, and after about three miles "inland," I arrived at the Hayward BART station. This was in the midst of rush hour, but BART revised their bike rules several years ago (or was that a decade or more ago), and restricted bikes only on the most crowded trains. The Richmond/Fremont line, which includes Hayward and Berkeley, has no restrictions on bicycles, so I was able to board the train and zip home.

I thank my local train/subway agencies for the forward thinking to provide reasonable bicycle access on the trains. My trip would not have been possible without them, and I would have been limited to public transit without the bicycle portion.

On the northern California Coast

[I wrote this back in August of 2010]

Well, I've been back for a week, so it seemed like time to write reflections on my Portland to Berkeley bicycle trip.

Why?

Why did I do it? Was it turning 50, the old "mid-life crisis" reaction? Maybe, but probably only a small amount. I'm pretty satisfied with life (career I love, good friends and family, the body working pretty well). Was it "because it was there"? Probably a bit. I had started to think about riding up to the AAPT conference, but summer plans (and prevailing winds) pointed me in the direction of a return ride. And, hey, with two months off every summer, why not spend a couple weeks on my bike? In the end, why I did it is probably a lot like why I'm a vegetarian: "All of the above."

Athletic accomplishment?

Many people are impressed with my ride, thinking it's quite an athletic feat. I'm not so sure it's that hard. One of the riders I met on my trip (Ineke, who is quite a commute/around town rider, but not a big cycle tourist) hit it right when she said "It's not so much about the legs as it is about the mind." Dalton, a 17 year old girl riding from Washington state to SF with her dad and 14 year old sister, also had a hint about what was going on when she asked me "Do you ever feel like just quitting?" I told her that I did often, and that seeing all the other riders on the Pacific Coast route is a great encouragement to complete my trip.

How much preparation did I do for the trip? Not that much. I rode a few 30-70 mile rides over the past year, and several 20 mile commutes home from work (in the fall I was great at 1-2 times/week, but this fell apart when it started getting dark early, when it was raining, and when I got a sore throat). Other than that, my bike is my primary means of getting around town, so I am on it almost daily for 2-10 miles of errands and commute from the subway to work. I think that being familiar with and comfortable on my bike, especially in traffic, is probably the best preparation I had for my trip.

So, can anyone jump on a bike and ride 900 miles? Probably not. But I believe that one doesn't need to do as much preparation as many would expect, especially if you are willing to plan your days as not that long, and are willing to take each day "slow and steady."

Equipment

In Oregon, my first night

I tend to overpack for just about anything, and while my tour was not a complete shift from this, I did cut down from what I might have packed on another day. My bike and packs weighed in at around 110-120 pounds (depending on how stocked up on food and water I was at any give time). My bike with racks, fenders, kickstand, etc. weighs close to 40 pounds. Not sure of the empty weight of my bags (two sets of panniers, one rear rack, one handlebar rack), but I clearly was carrying a lot of "stuff" in my bags.

Tent: I only have one tent, a wonderful self-supporting two-person tent. I could have saved some weight here, but it was nice to have the extra room inside. I didn't need it so much on this trip (no rain), but if it had rained, being able to put my bags inside is a great plus.

Stove etc.: I have an older MSR "Whisperlight" stove that burns white gas. The fuel bottle connects to the stove, so the stove itself is minimal in size and weight (you could easily put it in a small shoe). It burns hot, and can burn just about any liquid fuel you can find (although white gas can be found in almost any sporting goods store in the US). The stove does take priming (big flames at first), and I had a bit of "stove envy" when I saw other cyclists whip out their compressed gas stoves and have them give off nice blue flames on the light, but I'm trying not to replace good equipment I have just because there's something "better" available. I have a "cook set" that contains two pots, a pan, and two plastic cups. The pan I never used, and I had another cup so the cups I didn't need either. I have a stainless steel insulated coffee mug that fits nicely in my waterbottle cage (and holds drinks hot for hours!), so there's another cup. I think next time I'll leave the pan and plastic cups at home.

Clothing: I pretty much rode with just my wool outfit: long-sleeve and short sleeve jerseys, cycling shorts, and leg warmers. I had an extra pair of shorts and tights that I never used, but I think they were important to have (a cyclist needs to be able to care for her/his bottom in any conditions, and if it rains it's great to have a pair of dry shorts to change into). Perhaps the street shorts, pants, and sweat pants were a bit much--but the shorts were great for swimming in.

Making friends and acquaintences

Highway 1 on the Pacific Coast is probably the most social bicycle tour one can take. You can find a state campground with hiker/biker campsites about every 30-50 miles, and during the summer there are plenty of cycle tourists riding southbound (and a few northbound). Nights turn into social gatherings for those so inclined. I met several people who I have kept in touch with over this past year [I'm writing this section in June 2011], and will have a chance to visit with Morris this summer when I'm in his neighborhood in Arizona for three weeks for a teacher training.

Beachcomber Cafe, Trinidad, CA

My blog from the trip

I blogged my trip on CrazyGuyOnABike.com.

Today as a finals review "warm up" (although it ended up taking the whole period) I presented the students with four beakers of water: One with ice, one at room temp, one on a hot plate "low" (about 37C) and one boiling. I used Logger Pro to show the four temperatures on a projector screen (a sensor in each beaker). I asked them to use the skills they have learned in this class to analyze the relationship between temperature in F and in C. Half the class I told to set C as the IV, half F as IV.

The four beakers, with projected temperature readings behind

One student in particular was emphatic that "it's not fair to put something on the final that we haven't done in class." I told him and the class that they have the skills to analyze this relationship, even if they haven't seen it, and told them that applying their knowledge in a new situation shows real understanding. I said that the final will contain mostly the type of physics problems we've been working on, but that there will be one relationship that they haven't seen before. (I use Modeling Instruction curriculum that focuses on analyzing experimental data to develop physics concepts/models.)

I gave them a couple minutes to write down the temperatures in C, then switched the readings to F. One student pointed out that the temperatures readings kept changing. I agreed, and asked which digits seemed constant: All agreed that the "ones place" was constant. Since I don't worry too much about sig figs in my class, I suggested that this might lead us to decide to round off to the ones place in their results.

The students settled down to work. Here's what I noticed as I went around:

1. I had the beakers labeled 1, 2, 3, 4. Some of the students put 1, 2, 3, 4 as the IV (even though I had assigned each group what their IV should be). For the next period, I changed the labels to A, B, C, D and confusion did not appear.
2. My students use TI graphing calculators for processing data. They first create a graph of the data, then decide if the relationship looks linear or quadratic. I found a couple groups that were doing quadratic regressions instead of linear, and upon talking with them they admitted that they used quadratic regression "because the DV numbers were so large compared to IV." However, their "a" value (in y=ax2+bx+c) was in the 10-5 range. We discussed that this number was so small compared to the others, that it could be considered zero, and when we looked at their "b" and "c" values, they matched the y=ax+b values that other groups got.

When we did whiteboard presentations, we first looked at those with degrees C as the IV. I asked my students who had completed chemistry (not all have) if they remember the conversion equation, and a couple in each class did. They give the "F=(9/5)C + 32" solution. I then asked them what 9/5 is in decimal, and, tada, it's 1.8 which is the slope they got in their equations.

When rounded to two sig figs, almost all groups got 1.8 and 32 for slope and y-intercept (a couple got ± 1).

One whiteboard with F on Y axis, C on X

I then said, "So this equation is great for us Americans who go to a foreign country and need to convert from C to F. But what about foreigners who come here and want to convert from F to C?" I then rearranged the equation (probably should have had them do it, but was short on time), and the results were the slope and y-intercept the "T F is IV" group got.

One whiteboard with C on Y axis, F on X

At the end I asked how many felt comfortable that they had successful at analyzing this relationship, and most were positive about it.

It was a good day!

Lee

A new food cooperative opened on November 15 in Berkeley. The Berkeley Student Food Collective is open to anyone, student or not. Both members and non-members can shop, members receive a discount in exchange for work hours. I've shopped there a couple times, and the store is quite well stocked. It's just a small storefront, so don't expect to get eight types of rice and thirty varieties of coffee, but they do have a fairly decent selection of produce, bulk, packaged, and refrigerated items.Stop by the store, 2440 Bancroft Way, Berkeley, CA.

In the early 80's I was a member of Cooperative Connections at UC Berkeley, another small cooperative. We were in the basement of the student union, so we had a bit less public exposure. I wish them well, and encourage Berkeley folks to shop there, student or not.

Here's a animated logo I created, showing the '80's and '10's logos morphing:

On the Physics Modeling email list there has been a discussion of finding tangents to a parabolic curve using an Excel spreadsheet. The primary way we use this is when students graph position vs time of a ball rolling down a ramp. Students discover that the relationship can be modeled as a parabolic equation, x = at²+bt+c. If they can calculate the slope (velocity) at various times, they can then graph velocity vs time, and discover that this relationship is linear.

I have created a spreadsheet that will allow students to enter the their (1) quadratic function values, (2) Independent Variable range, (3) a chosen Independent Variable value and (4) the increment above and below it. The spreadsheet will then calculate and graph the "tangent" at that point (not exactly the tangent, but if they chose a small enough increment, it will look like a tangent).

A screenshot of the spreadsheet is below, and you can download a copy of the spreadsheet here.

With the batch of Spare the Air days in the San Francisco Bay Area in the last few weeks, I came up with an idea that would probably save a lot more gas than trying to get people to carpool and take transit (not that I'm suggesting we stop this, but I'm not sure how many people really switch on STA days). My thought would be to change the speed limit to 55 on Spare the Air days.

I'm not sure how legal this would be (with all the permanent 65 MPH signs), but at least all those huge fancy digital boards that CalTrans has could read "Today is Spare the Air: Please drive 55".

Do you like the idea? Call the Bay Area Air Quality Management District: 415-749-4900