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Teaching in LA

14 Jul

How I Do SBG — With POINTS

Posted in Uncategorized on 14.07.12 by Frank

Many people seem to do SBG just slightly differently from each other, so I figure I’d throw my flavor into the mix.

(This post is primarily for those familiar with SBG, Standards-Based Grading. If you’d like to learn more, I suggest these fantastic resources.)

Instead of telling you the whole system, I’ll go over just one piece that as far as I know, I do differently from most others – How the grade for each unit is calculated.

The old system

Last last year and the beginning of last year, I determined a student’s grade on a unit based on a tiered A/B/C system that I believe many other SBGers use, or something similar. Here’s how it worked (see grade tracking sheet below for reference): To get a C on the unit, get a 4 on all “C” objectives. To get a B on the unit, get a 4 on all “B” and “C” objectives. To get an A? Yep, 4s on “A”, “B”, and “C” objectives. What if you did that, except got a 3 on one “C” objective? Then you didn’t even get a C. D for you. The idea behind that was if you’re in that situation, a “C” objective should be pretty easy for you, and since it has such a huge impact on your grade, you should be very motivated to get that one objective done, which would then skyrocket your grade.

Below is the grade tracking sheet for last last year’s unit on waves and sound.
Waves – ! Study Guideline

Several things weren’t working for me…

Problems:

  • It’s possible that I just suck at explaining how this works since no other teacher seems to report major problems of their students not understanding their system, but this confuses the $#!+ out of my students. “C” objectives are the more “major”, fundamental stuff, and “A” objectives are the “minor” stuff. What? Seems backward. Not only is this a problem because they don’t know how to figure out their grade, but it’s difficult for me to explain how to improve their grade and why.
    T: Okay, right now you have all the ‘B’ objectives but not all the ‘C’ objectives. You need to focus on the ‘C’ objectives first so you can at least get a ‘C’.
    S: But aren’t the ‘B’ objectives worth more?
    T: … mm, that’s not how it works. Right now you’re missing a ‘C’ objective so you’re actually at a D. The first thing you should do is make sure you have at least a ‘C’, which means you need to get 4s on all the ‘C’ objectives.
    S: … I have a D???
    T: …
    S: …
  • Part of this system is used as motivation. That, I later realized, is actually bad. But it’s worse that the students don’t even get the motivational aspect because they don’t get the whole system.
  • Many units are emphasized differently, but are weighed the same (since they’re all A/B/C with no quantitative values). I don’t want the mechanical energy unit to count the same as the circular motion unit.

 

I had to remind myself that the purpose of a grade is to measure, not motivate. I was using the wrong tool for the wrong job.

So… to make my students hate me even more, I switched up the already-confusing grading system on them mid-semester! :oD Oh, the things you can get away with in this district. Sorry, teachers-who-aren’t-even-allowed-to-implement-SBG-at-their-schools :o(.

The new, current system

Instead of putting each objective at a different A/B/C level, I assign that objective a number of points. Yeah, I said it. There are points, which is like the dirty word in SBG, but I believe this still follows the spirit of SBG. “Big” objectives are worth 10 points. “Small” objectives are worth 5 points.

Below is the grade tracking sheet for this past year’s unit on waves and sound.

W – ! Objectives

Short version, if the student gets a 4 on that objective, they get those points. Their percentage grade on that unit is simply the number of points earned, over the number of points possible. (More details in the embedded document at the end of this post.)

So, what about the idea that you must get all the “important” stuff first to get a decent grade? Still works with this system. From the teacher standpoint, a student who gets all the “big” objectives and some “small” objectives does represent more mastery than a student who somehow gets most “small” objectives and few or no “big” objectives. From a student standpoint, the points tell them to go for the “big” objectives first. To get a high grade, the student still has to knock out the “big” objectives and most or all of the “small” objectives, just like before.

Improvements:

  • It’s easier to calculate their grade on the unit. They still don’t get it, but at least I don’t have such a hard time myself trying to explain it. “These are how many points you have. This is how many is possible. Take what you have, divide it by points possible.”
  • It’s so much easier to explain what to focus on to get their grade up and why.
    “There are several objectives you didn’t get. Of all of them, focus first on L2. It’s worth more points than the others. If you get L2, it will bring your grade up twice as much as if you got any other objective.”
  • This system IMO is now better geared at measuring and has lost the attempted motivational aspect. If the student shows mastery on a “small” but supposedly more difficult objective, then that’s what it is.
  • The weight of each unit depends on how many objectives are in that unit and whether they’re big or small objectives. A unit with many “big” objectives might be worth 65 points and is naturally worth more than a minor unit with few objectives, possibly worth 25 points.

 

Ever since switching to points, I haven’t missed the old system. The new system is still about evaluating students based on their mastery of content and skills.

Of course, this is not to say any system is better than the other, but like almost everything in teaching, what works in one class may not work as well in another. I’ve found my system so far works better for my students.

I’ll probably switch things up again this upcoming year, haha.

Below are other details of my grading system that may compliment what I’ve explained above, or just provide unnecessary or confusing detail:

Grading Rubric

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03 Dec

Video: Brainiacs – Electric Fence

Posted in Uncategorized on 03.12.11 by Frank

Link to video: Brainiacs – Electric Fence

How I use it

Before each “experiment”, pause the video and ask your students to predict what will happen. Have them discuss their predictions with their partner/group and write their prediction on their whiteboard (or call on them randomly, or have them write it on a sheet of paper). Continue playing the video clip. After the “experiment”, ask your students what actually happened (since sometimes they don’t pay attention, don’t catch important details, or just see the results differently than you may).

Worksheets

If you prefer the ready-out-of-the-box approach…

Worksheet by Dean Baird (veteran physics teacher at Rio Americano High School and host of Sacramento PTSOS)

Worksheet by Elisa Fanchiang (physics teacher at Animo Locke Tech Charter High School)

To download and save video to your computer

This works for any YouTube video (and sometimes other video services too)…

  • Go to keepvid.com: Click here to go to keepvid.com
  • Copy and paste the video link URL into the box and click the “Download” button
  • Save the video that’s your preferred format and resolution (or click the one labeled “Max 480p” if you’re not sure)
  • If your video program cannot view the file, try downloading and installing VLC media player

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03 Dec

Resources for NPTW (New Physics Teacher Workshop) Winter ’11

Posted in Uncategorized on 03.12.11 by Frank

Featured at Today’s Workshop

Links/Resources

Frank’s Demos

Not Featured at Today’s Workshop but Relevant or Worth Mentioning

Links/Resources

  • I do a few basic battery/wire/bulb labs, but you may have a hard time doing those if you don’t have batteries/wires/bulbs. If you’re the type to buy your own class materials (or you just need them urgently), you can buy batteries and wire pretty easily and at reasonable prices, but those little bulbs are generally pricey at hardware stores ($2-4 each). Try getting some cheap bulbs at your local dollar stores (a great place for teacher supplies in general). I found packs of 4/$1 at my favorite local dollar store. Also, if your students are normal for their age, they’ll want to add batteries in the circuit until the bulbs burn out. I recommend getting a string of old Christmas lights and removing the individual bulbs from their sockets for this purpose.
  • Global Physics Department (online physics teachers community) – Live online meetings every Wednesday.
  • Physics blogs – There are several physics teachers who also blog, giving us excellent resources and inspiring great conversations. I won’t try to post every blog, and there is no “best” blog, but I’ll point you to the blog of the guy who many would agree is the hub of the online physics community (Frank Noschese’s Action-Reaction). A great source for inspiration and discussion on physics content and pedagogy (and more!).

Labs/Activities

  • Squishy Circuits
    Targeted toward children, but you may find certain aspects useful. This was not featured at today’s workshop, but James’ Play-Doh resister reminded me of this. Addresses basic circuit concepts (open/closed circuits, Ohm’s Law, series/parallel circuits).
  • Scotch Tape electrostatics – There’s a simple electrostatics lab you can do using just a few pieces of Scotch tape. There’s a few variations of this, but I just found a random one on the internet.

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    03 Dec

    Magnet Through a Copper Tube

    Posted in Uncategorized on 03.12.11 by Frank

    Drop a magnet down this non-magnetic copper tube and witness the magic (physics) that is Lenz’s Law (or Eddy Currents… or… something).

    Ingredients:

    • A ~ 5 ft. copper pipe (I used 1/2″ diameter, might have to ask to get it cut to length at hardware store)
    • Strong “disc” or “ring” neodymium magnets with diameter less than pipe, (available for reasonable prices by searching for “neodymium magnets” on eBay)

    Directions:

    1. Establish that the copper is not magnetic. Have a student use the magnets to pick up something magnetic (paper clips, nose ring, etc.), then attempt to attract the copper pipe. It shouldn’t work. :o|
    2. Establish that gravity functions properly through the copper pipe. Have the student hold the pipe vertically, then drop an object (pen) through the pipe. Did the pen seem to accelerate down through the pipe at approximately 9.8 m/s/s? If yes, then physics is working.
    3. Do the same demonstration, but with a short stack of magnets long enough that they don’t flip in the pipe. After you drop the magnets at the top of the pipe, take a leisurely stroll to your desk and back, then reach out to catch the magnet.

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      03 Dec

      Electric Shocker Plans and Notes

      Posted in Uncategorized on 03.12.11 by Frank

      (Updated 1/18/2016)

      Deliver a (relatively) safe electric shock with this amusing device. Not recommended for individuals with heart problems.

      Here are the plans I used:

      Electric Shocker Plans by menkster


      (Document created by Lawrence Sverdrup)

      Materials notes:

      • For the 9V doorbell, I found one for around $10 (shipping included) on Amazon
      • The transformer costs around $10 at┬áHome Depot (make sure it steps up/down 10x, so a 120V/12V transformer)
      • Instead of the switch featured in the plans, I chose a momentary push button switch available at Home Depot┬ástores. I prefer the default state of the circuit be open, and closed only when intended to be, for only the duration intended.
      • For the handholds, I used cheap metal conduit, although any metal pipe should work. I used alligator wires to connect the handholds to the device.

      Usage ideas

      • You may want to remind students of a few concepts. They may be hesitant to fully grab the terminals. Actually, the more surface area contacting the terminal feels less intense than a small surface area of contact since a larger contact area means a larger cross-sectional area for the current to travel through. That’s why the feeling is most intense in the forearms and felt a lot less in the torso. Touching the terminal with a single finger is not a good idea.
      • Enforce the ideas of open circuits, closed circuits, and short circuits. If the student holds just one terminal, will he feel a shock? What if he held it with both hands? If the student holds both terminals, will he feel a shock? What if he holds both terminals together so that they’re touching? Will he feel a shock then? He may be shocked… intellectually! :oO
      • Demonstrate the inverse relationship between resistance and current in a series circuit (more resistance = less current) by having students hold hands to form a chain, then the students on the end of the chain each grab a terminal with their free hand (to form a complete loop). The more students in the chain, the less buzz they all feel. This also creates a snowball effect in getting more students to participate in the circle (since sometimes students can be quite hesitant). Also, hesitant students will want to stay away from the terminals and instead be in the “middle” of the chain. Prompt them to think whether there’s a difference in current in those positions.
      • In a one-student/shocker circuit, insert in series a large bowl of water (so one terminal is dipped in the water and the student’s hand that otherwise would be holding that terminal is instead dipped in the same water). Deliver shock. Salt the water to increase its conductivity. Deliver shock again. Have student feel the difference in conductivity. Try different liquids (Gatorade, etc., stuff with electrolytes, or distilled water, which shouldn’t conduct much. Blood would just be plain creepy.)
      • Set up the device to deliver a normal shock full strength to one student. Tell them to try to let go of the handholds when they feel the shock. Hold down the button and watch them try to let go. Explain that their muscles are controlled by electrical signals from their brain and that the signals of the shocker are stronger than those brain signals, so that’s why they’re unable to let go of the terminals, even though their brain is telling them to let go. Do a quick check for understanding by asking the student to summarize that in their own words. Evaluate the student’s response and provide feedback. Then, let go of the button.

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