Teacher perception of Energy Bar Charts and Tracking Diagrams

As a researcher and teacher, I have a certain understanding of the affordances and limitations of different energy representations.  But I also enjoy hearing some of the teachers’ perceptions of these representations so that I can compare with my own views.  That’s what this post starts to explore.  There could be important implications for instruction, but I don't get into that here.

Monday, 08/13/2021, table#2, pm

In a previous post (here) I described a particular class context and how three different groups (tables#2, #3, and #8) each used a different energy representation on their whiteboard to answer the same prompt.

In this post I will show and analyze an interesting clip from that same context where the teachers at table#2 explicitly compare their board (Energy Tracking) to that of table#3 (Energy Bar).  One reason I think this clip is interesting is because the teachers spontaneous contrast and compare the two boards and quickly pick up the key differences.  It’s also interesting because the different members have very different preferences.

For the video clip, Mary is on the left initially writing on the whiteboard, Sid has the blond curly hair on the foreground right and Julie has the straight brown hair at the back right.

The clip starts with table#2 answering several questions on chemical and thermal energy in lifting and lowering a bowling ball at constant speed.  Since the questions are on the screen at the front of the room, Mary is frequently looking back over her shoulder to see if she is getting all the details right.  So when, Joe, who has been working with table#3 on the same problems, brings his whiteboard up to the front of the room, she sees him do it.  (at 0.37 in this clip).

Finally, Mary finishes up and is mentally quite exhausted ,but she is also very intrigued (troubled?) by what she sees on Joe’s board (1:09).  From there follows a brief group discussion about what table#3 did (Energy Bars) compared to what table#2 did (Energy Tracking):

                Mary:  …and I’m done.

                 Julie:  laughs.

               Mary:  Is looking at Joe’s board at the front of the room (scratching her neck)

                 Julie:   I’m so sick of talking ab (Mary talks over her)

Mary:  What do you guys think of those bars?

 Julie:  I love the bars.

Mary:  Do you love the bars? 

    Sid:  Adjusting her view to see the front of the room.

Mary:  The only  thing I don’t like about the bars, but they seem to (garble) (points to the front of the room), it’s not clear where they come from (points to her group’s whiteboard to compare), like if you just did bar to bar (gestures with hands) you don’t have any…transfer (gestures with hands)

Julie:  Yeah, totally, transformation and conservation is all I see.  But I like it.

Mary:  But they’re showing it though (points again to front of room), with dot dotted lines are they?  (folds arms on chest)

    Sid:  Yes, but they’re also different SIZES (squeezing gestures with both hands).  In fact we can’t  do chemical going to two different things (garble).

Mary:  As far as (garble)…

 Julie:  laughs

Mary:  it’s not showing where it’s coming from.  It’s not showing the transfer.

 Julie:  (lays head on table) I like it for conservation.

   Sid:  It’s bound by (garble)  (gentle pounding motion by right hand)

 Julie:  (cheering) Go bars, go bars!

    Sid:   (garble) (head nodding).

Mary:  They’re elegant.

 Julie:  I’m so burned out on this scenario.  I’m burned out.

                                2:00-2:20 side conversation

Mary:  Looking at Sue (black top, grey skirt) at table#1 and/or the front of the room and mouths something (“what are they doing”??)

              Mary:  Did their…

Mary:  Gets up to get a better view of Joe’s board.  Tilts head at angle to better read it.  Sits back down.

                Mary:  I can not follow that one (pointing to Joe’s board).  It’s too…

                Julie:  Mary, let your brain rest.  You’re going to explode..hahaha.  You’re going to explode.

Starting at about 0:40 in this clip, Mary is repeatedly looking at Joe’s board as she finishes her other task.  It is really interesting  (different?) to her and keeps grabbing her attention.  Immediately upon finishing the task at hand, she is back looking at Joe’s board.  Her gestures and facial expressions are very interesting.  Maybe she feels some intrigue or perhaps puzzlement?   She has a slightly closed body position which might be expressing some uncertainty.  She looks a long time and then wants to know what her group thinks.

I’m fascinated that Julie’s response is immediate.  Perhaps this is part of her personality, to be spontaneous.  Clearly she is not as reserved as Mary.  Anyway, she has no hesitation whatsoever.  She loves bars.  But Mary is bothered that the bars don’t show the energy tracking.  She can’t see the specific transfers clearly, and in particular, where each form came from, although table#3 did put in dotted lines to indicate both some kind of tracking and that all bars had the same overall heights (see the second photo here).  I am interpreting the “they” in “it’s not clear where they come from” to refer to the different energy forms rather than to the Energy Bar representation itself.  I say that because of her hand motions (bar to bar) and her reference to the work on their own whiteboard, which she points to, and which explicitly used an Energy Tracking Diagram (see first photo here).

Julie completely agrees with Mary, but still likes bars.  She is able to immediately comprehend the two key features of the bars and the missing one – “There is no tracking, just transformation and conservation”.  Sid’s comments and tone of voice seem to indicate she doesn’t prefer Energy Bars either, but she doesn’t ever say so explicitly.  And Mary states even more unequivocally that the bars don’t show the energy transfers.  Julie knows why she likes bars – the conservation of energy is very clear in them for her (all bars are the same height, which can be seen in one quick glance). 

Here is a hypothesis about why Julie might prefer bars (or see energy conservation so clearly in them compared to tracking).  Conservation in energy tracking comes from counting the number of letters in two or more snapshots and comparing them.  The letters might be scattered across several different objects spatially arranged on the whiteboard, or, as in the case of table#2’s whiteboard for this problem, there are many different snapshots, with different length arrows showing the transforms.  So it is a little jumbled and perhaps difficult at first glance to see, although counting the number of transition “rows” in their diagram is also a way to see conservation, and the number neither increases nor decreases from beginning to end.  This is speculation on my part why Julie might like bars.  And she never really says she likes them better than tracking, so that is also speculation on my part.

Julie is totally psyched now (actually totally burned out if we believe her self-report, though her body language shows fatigue too I think) and starts cheering for the bars: “Go bars!  Go bars!” almost like it IS a competition between bars and tracking, and that she DOES like bars better than tracking.  And Mary certainly agrees that bars are “elegant” - aesthetically pleasing.

It’s clear that Mary is totally engrossed by the bars, working hard to try to figure them out.  Even though the other two pull her off-topic  after she sits down, after 20 seconds  she is right back at it, even getting  up to go look around people in the way, and tilting her body sideways to view the bars a different way.  At last she states a reason for all this querying and behavior – she can’t follow them.  So perhaps this whole time, since first glancing at them when Joe brought them up, she is puzzled and has been trying to figure them out, but her group doesn’t really explain them to her when she asks.  And possibly she can’t quite figure them out on her own.  And Julie just really doesn’t want to do any more on this scenario, so Mary stops after trying this second time.

Something curious about Julie’s response to loving bars is that she never draws them.  I’ve been watching the group all week and at least in the afternoons, only Sid and Mary have been drawing on the whiteboard.  And table#2 never had bars on any of their whiteboard photos that we have.  Apparently only table#3 ever does bars.  One possible reason that table#2 never did bars is that Julie never felt strongly enough about bars over tracking to insist on taking the pen and drawing bars.  But perhaps also she does not understand them in enough detail to draw them (they were never formally introduced in class, and only appeared in a Diagnoser question on-line, which table#3 took and ran with in at least three different cases).

What follows next is absolutely hilarious (to me and table#2) but I won’t say much about it.  I just thought it was so great that I wanted to share it with the public.  Mary tries one more time (her 3^rd attempt) to ask her group about how the bars compare to their tracking, but Julie shuts her down, apparently for health and/or safety reasons:

                Mary:  laughing (garble, asking something pointing to their WB)

                Julie:  You may not look at this (whiteboard) again.

                Mary:  Hand motions of heat from her head.

                    Sid:  Thermal energy, thermal energy.

Julie:  What’s that smell?  It’s like her hair is smoldering…Gosh, Mary, take a break. (fanning Mary with her hand to cool her off).

Mary:  Slouched with her arm grabbing her neck and laughing uproariously.

    Sid:  She’s got too much thermal energy (gently fanning Mary with the whiteboard)…(garble) too much chemical, breaking their bonds.  That’s the evidence we have.

Mary:  Relaxed sitting.

 Julie:  Mary is, all of a sudden Mary is…kapoo (makes blowing up sound and gestures with hands), her head explodes.  Ohhh…take a break Mary, walk it off.

                Mary:  Waves hands in front of chest to cool herself off.

Notice the excellent evidence-based reasoning that Sid is using to justify her statement about which energy transfers she thinks are going on in Mary’s head.

Alex Congress Presentation

A quick rundown of my history at the University of Illinois and the University of Texas.  Except for teaching experience, my background is fairly far removed from PER but I am trying to transition into PER now that my PhD is wrapped up.

The first clip, which I blogged about here, shows teachers co-creating the idea that energy is shared between the magnet and the ball bearing.  This clip appealed to me because of the general productivity of the interaction and the way the teachers each built off each other's ideas.   This clip could be viewed in terms of the teachers' epistemology and how they frame their current activity and interaction, in terms of the cognitive resources the teachers bring to the discussion, and in terms of the teachers' use of tools and gestures to communicate and to aid their group cognition.

I shared some things I noticed while watching the clip.  Some observations from other I-RISEer's:

• Is this form of "argumentation" always productive or are there times you need more explicit rejection of incorrect ideas?
• The importance of differentiating between attacking an idea and attacking the person who proposed the idea
• Teachers are doing more than just referencing each other's ideas, they are engaging with them - playing them out to see where they lead.
• The teachers start with observations and then transition to sense-making, this pattern repeats as Sid shares her observation about magnet strength.
• The amount of hedging versus ownership of ideas might be related to how comfortable each teacher feels in that group (note: Sid and Julie have known each other for a long time).

The second clip starts immediately after the first clip as Lane shifts the teachers' attention to the third question on the worksheet that accompanies the Gaussian Gun activity.

I wanted to contrast the great interaction and "discussion" framing in Clip #1 with the reduced interaction and "worksheet" framing in Clip #2 (at least until Lane gets up).  Both video clips start with the teachers attempting to answer a question from the worksheet.  In the first clip the worksheet question prompts a very productive interaction while in the second clip the worksheet question prompts a much less desirable interaction.  My claim is that this is due to the wording of the questions.  The language of first question (energy gains and losses for the ball and the magnet) matches the language the teachers were already prepared to use to discuss the Gaussian Gun - it matches language the teachers had already developed during the first week of the workshop.  The language of the second question (energy associated with the interaction) does not match the language the teachers had already developed (energy shared between the ball and the magnet).  While Lane recognizes "shared energy" and "energy in the interaction" as very similar ideas the difference in language causes the ideas to feel disjoint to the teachers.  When Lane directs the teachers to the worksheet question, the shift in language causes the teachers to shift their framing and hence their interaction.  At least until Lane gets up and Mary returns to the "shares it" language.

Some observations from the I-RISE team:

• Lane cuts Mary off in his excitement to offer them the "interaction" language to describe their idea.  This interruption likely contributes to the shift in the group dynamics.
• If the instructor's goal was to get the teachers to say a specific word or answer a specific question then this could feel like a very productive interaction.
• The second video starts with everyone agreeing "associated with the interaction".  Even if the teachers aren't sure exactly what this means they have already agreed on an answer.  There is little opportunity to co-create knowledge once everyone agrees on an answer.

Overall it's been a great experience and a great two and a half weeks.  I want to keep looking at this video and thinking about the effects of language and framing and group dynamics.  I also want to keep thinking about energy forms (specifically, when is energy thermal vs. sound vs. kinetic) and also whiteboard use (specifically, when and how is the whiteboard used a shared tool that everyone interacts with to aid the group cognition).

Abigail Daane IRISE Presentation E2

Slide 1

Slide 2

The above slide 2 should look vaguely familiar to those who saw my understanding energy presentation. I didn't spend much time on describing my background because most people in this group know my background.

Slide 3

 Again - slide 3 should look familiar to UE peeps, but the point of slide three is to orient people to my interest in thermal energy and its special status from last year.  I feel like this is especially relevant to this presentation, because part of the reason I picked out this sequence of episodes was that the ideas from last year appeared to influence this year's focus and attention to thermal energy.

Slide 4

Slide 4 gets into the new data from E2. The sequence of videos I present below are all from the same post from a couple of weeks ago found here. The claim I make is that the teachers from E1 last year, in this case Kim and Jessica, use thermal energy to the the scapegoat for the energy they see as imperceptible.  I used the word scapegoat as sort of a "first order idea" that they settle on immediately.  I didn't really think about using the word "scapegoat" to be a finished product and some people seemed to worry about using that word.  Here are two definitions stolen from http://dictionary.reference.com/browse/scapegoat:

Scapegoat
1.      a person or group made to bear the blame for others or to suffer in their place.

2.

Chiefly Biblical . a goat  let loose in the wilderness on Yom Kippur after the high priest symbolically laid the sins of the people on its head. Lev. 16:8,10,26.

Suggestions from Brian, Sam, Rachel, (and others?) were made to change scapegoat to:
- "pinning it on thermal" or
- "thermal is a catch all" or
- "thermal is an assumption" or
- "thermal is a way of glossing over the ideas".
Brian, correct me if I am wrong, but I think that you were reacting to the negative context of scapegoat.  However, I think that it really is suggested to 'bear the blame/responsibility for others' in this case.

After a long conversation though, it seems to me that I now interpret this set of videos a bit differently in terms of what Kim may or may not be thinking.  Originally, I think that Kim does suggest it all goes to thermal, however, she doesn't immediately suggest the idea that the car bounces back, so I think that she is thinking of an inelastic collision, where it is like a lump of clay and the energy all ends up as thermal energy.
Some suggested that she was looking at the initial and final state only, not at the process in between.  This is definitely not ruled out for me yet, but I am going to push back on what Sam and Brian said about her thinking of only the final state, because she tries to justify the thermal going back into kinetic by using the squash ball example. (This is not in the sequence of videos I post, but in between them). In this situation, she says that you have to warm up the ball to make it elastic - so you have thermal energy making it more elastic.
In talking to Sam after the Congress, it seems that another option might be that Kim had two ideas, one about the inelastic collision (where she suggested thermal energy) and one about the thermal going into kinetic, but that she didn't connect those ideas until Stamatis brought them up again.

Jessica, on the other hand, was operating under the assumption that the energy went from KE -> TE -> KE. I was under the impression that Kim was following what Jessica was saying, and that she agreed, but some pointed out she could have been agreeing without listening/hearing what Jessica was saying.

Slide 5

Slide 5 introduced Video 2 where Stamatis asks "What process takes thermal energy and turns it into kinetic energy?"  The teachers respond easily with several examples, a generator, combustion, a firecracker.  However, they seem not to understand that this question was in reference to the situation at hand.  Jessica realizes it later and is quick to then draw the conclusion that Stamatis doesn't think it is possible for thermal energy to transform into kinetic energy in this scenario.

Brian pointed out that teachers use lots of examples of thermal turning into kinetic energy (popcorn jumping off the skillet, bacon grease, or water popping off the hot skillet). I have never thought about these examples before, and I need to think about them some more.

Slide 6

Slide 6 is about video 3, which follows Kim's description of squash balls needing thermal energy to be bouncy. This idea seems to imply that she is trying to justify the idea that thermal energy is being used to bounce the car back and turns into kinetic energy.  However, I need to go back and look at this part of the video to see if that is actually the case, now that I have increased my understandings of the number of possible interpretations about what Kim was thinking.  In Video 3, this is the first time that elastic energy is mentioned at all.  Akbar uses Kim's example of the squash ball to build upon it and suggest elastic energy as being the reason it bounces off.  Jessica takes up that idea.

Slide 7

In Slide 7, video 4 shows Kim apparently not realizing/hearing/understanding/connecting the idea that thermal energy had been suggested to be in the middle of the process until Stamatis is restating what was said previously.

Someone pointed out (I think Alex) that because they were thinking of the chair as the only other object in the scenario, that perhaps it was more aligned with the general ideas the teachers have about the environment, and our ideas about the environment essentially being a pool or reservoir for thermal energy.

Slide 8

The Takeaways:
1. There was an assumption made that the imperceptible energy was thermal energy, before the process was dissected and a mechanism was identified.
2. This was one of the few examples that Stamatis has seen where the teachers suggest that the thermal energy converts back into kinetic energy.

After my presentation:
Stamatis mentioned that my AAPT talk went over well with the teachers, and that my efforts to make them understand how important their ideas were to my research was well-received. This was really good to hear.  I sincerely hope that they choose to stay involved with the EP, and that we have a chance to go to their classrooms more to observe them in action.  Also, I wanted to make sure that I recorded the fact that Leslie was worried about how sound was involved in spreading energy and how that tied into our story.  I replied that sound and light have not been a major focus yet, but that those ideas need to be included in the story.  He also suggested I look at the KWE (Kinetic Wave Energy) discussions of E2 to check for connections to spreading.

Next Steps: 
1. Watch the squash ball part with Sam.
2. Talk about how this relates back to the other videos.  Sam suggested that their readily available examples of how thermal energy is perceptible and can be used productively help to point out that teachers do not always view thermal energy as useless, degraded, or imperceptible.  This seems to imply that there is something about the scale/amount of thermal energy that is important.  The smaller amounts seem imperceptible, and yet the large amounts are significant and easy to perceive.
3. Check out the KWE discussions in E2 to see if that relates to energy spreading.
4. Theoretical ties?  Do I have any? I feel like I didn't include any theory. Hm.

There's Literacy....And then there's more

Happy Friday Everyone,
I must say that I've learned a lot from being an I-RISE scholar. I've been enjoying the words of advise that I've been receiving from the teachers in the E1 class, as well as from the other I-RISE scholars. I've been reviewing the videos from before searching for one a clips that have resonated in my mind enough to post and discuss about. Thank fully I have found several. The first one that I am sharing is from the first day that I was able to take notes on PrimaryPad which is actually the second day of the class.
The teachers had their first experience with Energy Theater on that day. Lane gets them prepared for Energy Theater by having a whole class discussion about energy. The teachers in the E1 class mentioned how they have to be careful with the words they use in their classrooms to prevent their students from being confused. One of the teachers complaied about using the words "change" and "transform". Another teacher debated with the class as to whether or not they should be on the same page when it comes to teaching in general. Julie, who is sitting at table 2 made a remark that's been stuck in my head ever since. Here it is-

Clip taken from: E1 120807 1018 T2.mp4

I've experienced some classrooms in the Chicago/Chicagoland area where there is more taking than "do-ing". I agree what Julie has said wholeheartedly. Focusing on words and terms, although important, increases the chances for students to miss out what "do-ing" science has to offer. I think believe that's what makes Energy Theater so important. It's an excellent tool to "do" science and define and relate to the terms.

Engagement and personalities

My observations today (8.16.12) were focussed on a group consisting of Sam, Sarah, and Christine. I found the interplay of their personalities to be very interesting. In order to properly frame these interactions, I should note that my observations occurred one day after the class had revisited it's classroom expectations. This recovering of expectations had a noticeable impact on Sam's behavior.

To begin the day the three of them were working their assignment as a single group. Within this group, Sam took an active role as the group leader (something I hadn't seen much of previously). In this role he largely acted as the source of knowledge. He told the other two how things worked and they could ask questions. Christine was willing to engage within the group dynamic, asking a fair number of questions. Sarah engaged in asking questions, but less then Christine. Sam worked somewhat diligently at answer the questions, using a variety of examples.

Eventually, however, Christine left the group to work with another neighbor. While I couldn't hear their conversation, from observing their physical interactions and expressions they appeared to working together on the whiteboard in a fairly lively back and forth. This left Sam and Sarah to work together. In this setting Sam began by giving Sarah explanations to her questions. But this quickly ran aground as Sarah stopped asking questions. The two of them then proceeded to sit for extended periods of time either working on their own papers or simple looking at other groups. Sarah appeared to look at Christine's group with what I interpreted as longing.

After a break Christine came back to the group and Sam took his computer to side of the room. With Christine and Sarah working together, they jointly discussed a wide variety of ideas and were highly productive. Sam appeared to be engaging in physics readings and/or videos, but it was not completely clear.

To understand why these interactions occurred as they did I find it useful to employ Lave and Wenger's idea of communities of practice. The Energy Project employs a set of classroom norms that differ from the typical K-12 classroom. Most classrooms operate using a transmissionist paradigm, in which knowledge and authority derives from a top-down structure. In Energy Project the instructors and the students (teachers in this case) create a community of learners in which there still remains differentiated roles, but the power higher-archy is greatly reduced. As a way to increase teacher buy-in for this model and to create a more jointly-negotiated set of norms (a requisite to creating a community of learners) the teachers were explicitly asked what norms they'd like to observe during the class.

Most of the teachers quickly took to the community norms of the community, which included the participation and valuing of all members ideas regardless of their alignment with the accepted scientific models. Once these norms were accepted the teachers began taking a fairly rapid transition from peripheral participants to full participants. This full participation was visible through the teachers willingness to push on the direction that the group takes (whether that's changing the questions on worksheets, determining what activities should be done next, or enforcing the group norms on other members). However, I think that while Sam is a member of the community, he never made that transition to full participant.

Sam can be seen trying to change the group dynamics to a more traditional transmissionist style learning, but as a peripheral participant he doesn't have enough status within the group to make those kind of changes. Even in small groups, the negotiation of how things will be done does not work for him. Group members either leave his group or stop participating. Because of this mismatch of expectations (between answer seeking and sense-making), Sam often leaves groups to engage in answer seeking by looking up information on his laptop.

I should also add that I saw similar interactions in my video clips from the day before where Sarah would often shut down when the group engaged in answer seeking. More analysis of this will be included in my final presentation.

E1: Sound and thermal energy

The teachers in the episode below have been discussing the forms of energy that are associated with a whistle.  This question has prompted them to wonder what is the difference between sound and thermal and kinetic energy.  Here's a snippet from that conversation.  (The stuff in the middle is less interesting to me than the stuff at the beginning and end, so if you don't have time to watch the whole thing, skip 1:54-4:40ish.)

Episode title: E1 120810 1448 T7 sound vs thermal

Transcript: [00:00:00.00] Sid: Okay.  How does it become patterned?  Do you know what I mean?  Like, so there's heat (inaudible) and then sound is this motion energy that is, how does it get in a pattern?  As opposed to?
Off screen: How does it get in what?

[00:00:14.27] Sid: Actually get in a pattern.
Side talk about "pattern."
Julie: We spent the entire ride home yesterday, we did like 25 different accents as we were driving.  So, I hear a pattern, like she says, 'pattern.' (Laughter)  More talk about pattern.

[00:00:46.29] Lane: Now let's respect your question, how does it get in a pattern?
Sid: Yeah, what, what?
(Inaudible comment off screen)
Sid: What makes the atoms all be sound, so that it goes (inaudible).

[00:01:05.03] Wendy (?): Well they're all random till they get hit by the speaker.
Sid: Yeah, but why?  Why, what makes it?
Steve: So, the cone of the speaker is physically pushing the air.
Debra: Yeah.

[00:01:13.06] Bryan: Change the amplitude [on the PhET sim], Lane, and then watch what happens.
Steve: If you look, you can see the cone of the speaker actually moving.
Lane: Change the amplitude. (inaudible)
Sid: Allright, so here's another question that went with that: During this sound production, is heat also produced?
(Lots of 'sure's, 'yes'es.)

[00:01:32.27] Sid: So why would those particles jiggling be random, but the jiggling of the other atoms be patterned?  If they're being produced at the same time?
Lane (and others): Hmmm.
Steve: Eventually, all that sound energy is gonna dissipate, because the sound's not gonna go on forever, it's gonna spread out, and it's just gonna heat up the environment.

[00:01:54.26] Lane: Let's see if that's true.  (Messing with PhET sim.)  I'm just curious. (inaudible)
Debra: I wanna see the light one.  Uh, what is this?
Lane: Well, Steve is making the claim that [all that pattern.] I turned off the speaker, and Steve claims that all that pattern will (dissipate?).
Debra: [What just happened?]

[00:02:10.20] Debra: Oh.
(Oh!  Wow!  In the background.)
Debra: Oh, so much for Brownian motion.
Someone in background: That's what air looks like!  Just like that. 
(It's hard to hear what others are saying because there's a lot of side talk, and Debra is mic'ed.)

[00:02:27.05] Debra: They twitched.  That's so weird.
Wendy: In the corner.
(Talking about sim and laughing.)
Alia: Wouldn't it be interesting if it actually showed us the sound that it was making?

[00:02:46.14] Lane: Where does the sound energy go, right?
Debra: That's funny.
Lane: As soon as I get out of class today, I'm going to email the PhET (inaudible) and say where did they go?
Debra: That's right.  Shoot em a email.

[00:02:57.27] Lane: It seemed like it went away.
Debra: What's...
Lane: If I listen to Feynman, I say not only does the air no longer have thermal energy in it...
Someone off camera: It's a solid!
Lane: It's a solid.
(Laughter)

[00:03:12.26] Off screen: (You've got to make a really big noise) to liquify the air.
Lane: Noah Finkelstein is gonna hear from me.
Debra: Finkelst. (Laugh)
(Lots of talking.)

[00:03:53.26] Debra: Can you show that, is there a...
Lane: (Some feature of sim?) are just a way of helping you focus on one particle.
Debra: Can you show, add the detector?
Lane: What's that?
Debra: Can you add the detector?

[00:04:11.02] Lane: The detector?
Debra: It's at the...
Lane: Yeah, it's not going to be very exciting, I don't think.  It might, I don't know.  So it's measuring the air pressure at a specific location, but I can pick.  So I wanna go there.
Debra: Does that help you?  Bryan?  Does that make sense to you?

[00:04:42.23] Bryan: Yeah.  It made sense, I just couldn't get past the (inaudible).
Joe: So the difference between sound and heat, right, to me, right, has to do with, we all talk about vibration makes sound, and the difference between vibration and other things is the fact that it's in patterned, regular intervals, right?
Sid: And (inaudible -- interacting with something?).

[00:04:56.09] Joe: With the air.
Sid: Yes.
Joe: That's why they say you can't hear in space, right?
Sid: (inaudible -- speaker hitting the air), that's creating the jiggling (inaudible)

[00:05:03.21] Debra: Exactly, that's why you can't hear in space.
Sid: (inaudible)
Debra: Vocal cords.
Joe: But what I don't buy is that there are things that I can't picture vibrating but that still make sound.

[00:05:17.28] Joe: I wish I could think of an example now that I said that out loud, but, uh.  There are things (someone clapping) that I don't picture producing that kind of vibration (someone dragging chair on the ground) but I know it makes noise.
(Yeahs from around the room.)
Debra: Yeah, I'm thinkin' skid.

[00:05:32.06] Joe: How did that make an evenly distributed disturbance?
Sid: Yeah.
Joe: That was just weird and irregular, but yet it made (inaudible).
(General agreement from the room.)

[00:05:41.06] Don: Slip a stick on the floor.
Sid: Maybe it's a bunch of individual, one-pulse noises.
Joe: So what does a one-pulse noise look like or sound like.  Can you hear that?  Is there such a thing? Is it possible to have a one-pulse noise?  I don't know.  (inaudible)  I'm done.

[00:06:05.21] Lane: So, Joe, you're gonna do this, [you're gonna] do a reading uh, this weekend that will, not answer that question, but...
Debra: [Don't cry.]
Someone in background: Of course not!
Lane: ...it's probably turn the screws a little more.
Joe: That's good.

Commentary: This episode caught my eye because of the questions that Sid and Joe ask -- how does sound become patterned; is heat always produced when sound is; oh!, so that's why you can't hear in space; and how do not-obviously-vibrating things make sound?  I don't know the answers to these questions -- at least not deeply know.

And I wanted to clip this for Alex (and maybe Sam).  I'm interested to hear what they think.

Exploiting classroom context, exploring physical context

Last thursday morning group#1 used the classroom context to get an initial hint to solve a problem but then subsequently spent a considerable amount of time spontaneously varying the physical context of the problem itself to buttress and refine their first insight.  The former I usually consider disappointing because it’s a kind of hidden curriculum that is not part of “authentic practice” and so is not so useful to learners outside school.  The later I consider a sophisticated problem-solving approach that I hope learners realize is a part of what it means to think like a scientist/physicist.  Further, group#1 took the idea of changing the physical context and applied it to a new and very different problem later in the morning.  I thought this showed the amazing kind of science reasoning and transfer ability that teachers can do.  What follows are the details of this scenario.

The E1 class was working on the spool and string problem.  Lane had demonstrated that pulling straight up on the string caused the spool to roll faster and faster and faster across the floor.  He reminded them that earlier that morning the class had agreed that “If an object experiences a net force in the same direction it is moving it will speed up.”  Then he gave the problem that since the spool was clearly speeding up, the groups' task was to decide what force was causing the speeding up.

The importance or usefulness of context then came up in two different contexts for table#1.  ^_^

At the start of this task (see video) Desi seems to be in a kind of classroom context, answer-making mode.  She blurts out feature-talk words (“momentum”, “torque”) that have not really come up before and cites her daughter, NPR, and the Olympics as the source of part of her knowledge.  It seems like she is grabbing for a word to label the effect Lane demonstrated.  This is not how she usually contributed to the group, so I was surprised (caution, 8 minute video; it's so interesting I wanted to show it all).

While they were still talking about what the force might be Desi then noticed (1:09 of the first clip) that Lane and Adam were filling a tub with water: 

“now they’re filling up this thing because I have a, and I’m going to make a reasonable guess they’re going to do the same thing in water and it won’t move the same way, it’s just going to spin (stay in place)”

She reasoned they might be trying to eliminate friction (she was thinking about friction all day and bringing it up in all the activities - it was interesting to see how it was a thread in her thinking the whole day when discussing slowing down or speeding up).  This is how she used the classroom context to get a hint for solving the problem.

After that initial idea spark, the group goes on to bring up many wonderful relevant examples from everyday life or their personal experience with each person building on the previous person’s thoughts, and using sophisticated reasoning like limiting cases:

(i)                 Their first example is that the wheels on a training bike have to touch the ground firmly, otherwise they won’t provide traction, they won’t spin.

(ii)               Vickie modifies the spool context further in a limiting case kind of way by talking about the spool in the air so there’s no contact with the ground (ground is lots of friction, water is less, and air is even less).

(iii)             Desi puts the two together:

“Bike tire spinning in the air, there’s still some friction being created with its contact with the atmosphere, but not enough friction to invoke, or induce movement (forward)”

(iv)             Jenna takes the limiting case reasoning and runs it backward to talk about the contact force by the floor on the spool:

“…so this force has to increase in this particular area (pointing to WB) relative to everything else”,

(v)               Desi runs with Jenna’s idea and connects to both the static case of no movement as well as the net force for speeding up:

“(the) pull increases the net force, which means force on this end changes enough so that the spool can move”

I think her reasoning here is that pulling up on the string causes the backward force to increase, so the forward friction force increases as well,

(vi)             Sue extends the context even further by discussing other ways to change the friction (aside from water or air):

“can increase friction by having a heavier spool (“right”) or having a (harder) friction surface”

(vii)           Jenna extends that idea by relating it to another personal experience of gears on a bicycle and changing the diameter of the spool (which seems to me more getting at the physics idea of rotational force or torque):

“makes me think of gears on a bicycle, so if this spool was smaller or larger, it would change”

(viii)         And then Sue brings it completely full circle by connecting the spool problem that started all this reasoning with a major previous problem – the mousetrap car (which they saw the first day and worked on the two days previous to today using both energy and force stories).  Vicki runs with Sue’s suggestion.

Sue:      reminding me of the (mousetrap) car

Vicki:  yeah, me too (draws on WB) 

Jenna:  oh, absolutely

Vicki:  (gestures with her hand, like it’s a lever arm) so instead of his hand (pulling up on the spool string) it’s the lever pulling that string (on the mousetrap car), and making it (the mousetrap car) go

I see this as expert-like listening, teamwork and reasoning as they build upon what each other says, modify the surface/object interaction to develop their intuition, and connect to previous scenarios from their life as well as what they previously studied extensively in class. 

I don’t know if they needed the hint that Desi picked up on, but they sure took off once she enunciated it.  But somehow they are not as confident as I would expect.  Because it seems like when they are all done, near the end of the clip, they go back to a kind of classroom-context type of reasoning.  Because they’ve finished early, before anyone else, they must have made a mistake, or not done something right or well.  They’re very nervous about their performance.  Vickie starts it, but Jenna joins and then Desi does too (they’re all talking over each other so I just can’t tell if Sue thinks that as well or not; she doesn’t object when Desi clearly states this nervousness to Lane):

              Sue: (looking around) are we done?  (puts red cup on top)

            Vicki: if we’re done early, I’m thinking we oversimplified it, we haven’t analyzed it enough, we’ve not tweaked it enough

           Jenna:  haven’t done enough

Desi:  That’s our disclaimer.  That’s our disclaimer every time.  We have a disclaimer (to Lane) Based on our current level of knowledge, this is how we understand the situation.

But they come back strong again on the next activity.  So after a 15 minute whole class discussion where every group shares what they did on the spool problem, Lane starts a very different activity.  The goal of this activity is to watch a video of an outdoor classroom of eight fifth graders and their instructor and try to tease out what ideas the different students might have as they explain their reasoning to their instructor.  In the video the students kick a soccer ball on a grass field and talk with their instructor about what it does and why they think it does that.

 

I won’t go into a lot of detail here but I’ve cut out two more clips from table #1 talking about what they saw in this video.  And even though it’s about kicking a soccer ball rather than pulling a spool, and even though it’s about the ball slowing down rather than the spool speeding up, after answering Lanes’ initial question table#2 very quickly starts connecting this problem to their the previous problem about the spool as well as their personal experience.  They’re playing with ideas again in a seemingly effortless way.  They talk about how what the kids did is not what table#1 did.  That the kids didn’t think about the surface, the environment, and table#2 discusses ways they could try to help their own students make sense of a kicked soccer ball.

For example, Sue talks about her experience playing soccer as a youth and how the different fields (tall grass, artificial turf ) had a huge and obvious effect that she and her teammates suddenly had to account for. And that she could use this with her students (about 55sec in):

I don’t think it looks that unobvious, I played soccer as youth, play on different fields, don’t think it would be that hard to make obvious, what’s making stop faster in big tall grass vs. making it go forever on this turf, all of a sudden they’re going to shift their perspective to a whole other object is involved.

 

And Jenna connects it back to the spool problem they just did (though I'm not sure the group takes up her idea, as Desi says "no, underwater soccer", perhaps missing Jenna's point):

Or does it matter which environment it’s in, you’re still going to be.. the same.

It’s kind of like putting it (the spool) in the water vs rollling on the floor

So again they continue with what seems to me to be an expert-like approach to physics reasoning.

So the initial classroom context of the spool problem kind of “gave” them an answer.  But they ran with it.  And really seem to have taken it up, because they were able to apply it in an entirely different sort of problem they did subsequently.

             - brant hinrichs