Thursday, June 27, 2013

SOCS-I Minstrell (Explaining the "at rest" condition of an object)

So, I have to say I was glad to have a shorter assignment tonight.  There must be something about reading heady articles at night in the summer time as a teacher, but I am finding it really hard to concentrate.  Anyway, this article was a nice easy read I could agree with.  I always have a ton of difficulty with the normal force, or as my kids all call it (regardless of what I call it) the "Natural Force."  Anyway, I spend a lot of time talking about it, but nothing seems to help.  I am not sure why I never thought of it, but having kids come up to the front and hold out their arms while I put books in them seems AWESOME.  I mean, how obvious, and yet this simple demo has eluded me for years.  I am excited to do this next year.  I think my students will immediately see the connection.  Maybe I am just fooling myself though :)  This year, in our discussions on the normal force, it came up that contact forces kind of don't exist.  I asked what our skin is made out of.  They said protons, neutrons and electrons.  Then I asked, what about the table.  Same answer.  Then I said, do you think these things interact with one another?  Then I asked, so....do you think you can actually "touch" anything?  They absolutely freaked out!  It was awesome, and it continued to be a topic of conversation all year.

SOCS-I Arons 2.8-2.16

S, in reading these sections of Arons, it became clear to me that he finds it very important to go over the base meaning of things over and over again.  That is, as we have been doing in class quite regularly, he thinks we should not just come up with a operational definition of a concept and move on.  He thinks we should force the students to think through simple examples like, if a ball is going up at 30 m/s, how fast will it be going in one second, two, three, four... and so on.  I think I am going to incorporate more of this into my classroom, but I wonder if my students will become tired of that kind of interaction.  I feel like after the first response the rest can come quite easily even if there is not a clear understanding by everyone in the room.  Perhaps the time at the top will cause difficulty, but otherwise, I see my students being frustrated by the slower pace.  Of course, I also feel like I am falling into the typical trap of a physics teacher-  If we clearly stated what happens, they must understand it now.  So, I intend on trying this repetitive process next year to see what kind of response it garners, and what kind of effect on understanding it has for the group.

Tuesday, June 25, 2013

SOCS - I (Hammer "Two approaches to learning Physics")

So after reading the Hammer article I find myself linking his two example kids to my own students.  I would actually be happy with either kid, as both seem motivated to learn.  Liza seemed to me what I call a memorizer, and Ellen a conceptualizer.  I wonder what a group of those two together would do for both of them.  This article makes me think of what I am doing in my classroom unknowingly to support students like Liza, as most of my "good" students follow this model.  I also wonder what I could do to help students like Ellen to gain organize and connect her conceptual thinking to her mathematical methods of problem solving.  There has to be a middle ground, and I have to support learning there.

SOCS-C Mestre "Learning and Instruction in Pre-College Physical Science

The Mestre article got me thinking about the Millikan Award acceptance speech by David Griffiths in 1997.  Both authors spent some time discussing textbooks.  Griffiths worries that spending more time developing concepts in the classroom necessitates students learning more "information" outside of class from the textbook.  He points out that, not only do many students find it difficult to learn from a text, but that most texts are not designed to present material without the guidance of a gifted instructor.  Mestre has similar things to say, I think.  He argues that the textbooks merely present a list of facts and problems for students to memorize and complete.  I agree that textbooks in physics are poorly written for high school classes, but it does get me thinking about how I picked up the conceptual understanding I currently have.

I seem to have arrived at a conceptual understanding through solving problems in textbooks without much direct guidance.  Then I would ask questions that came up through my solution, or more likely, I would be graded on a problem and realize my error.  Over time, and through repetition of this process, I gained the understanding I now have.  Through many failures and successes I have learned something that I do not think I could have learned without both the failures and the successes.  Science is hard, but it feels good to overcome a conceptual road block.  I think it is important to realize in all of this, that my expectation of my students cannot be mastery in the first run through.  Perhaps I need to reevaluate my goals/assessments looking forward.  I need to make sure my expectations of my students are in line with my reaction to my own experiences as a student.

Monday, June 24, 2013

SOCS-P (Arons 2.1-2.7)

So, reading Arons and his discussion of a "clock reading" as having zero length in time causes difficulty for me.  I immediately struck up a text message stream with my physics professor from college discussing this idea.  I will share it tomorrow in class with anyone if you are interested.  For me, if I am interested in describing instantaneous velocity and acceleration, I must inherently be discussing TWO TIMES.  Therefore an "instant" is by default a very small change in time.  Arons expressly states that an "instant" has no "length in time" just as a point has no length in space.  I guess this is semantics, but I really think it would hinder a discussion of any kinematic topic other than position.  To describe a velocity or an acceleration, two moments in time are needed, and both are the rate of change of one quantity per unit change of another.  If I go about describing an instant as being a single time with no "change" than I feel like I would have difficulty describing to a student why the "instantaneous acceleration" of an object at the top of its path is not zero.  I always talk about the fact that we are interested in two times, however close together they are, and an object will only be at rest one of those moments.  The acceleration will not be zero because the velocity is changing between those TWO times.  I have always described it this way, and I talk to my students about the fact that "instantaneous" really is an "average" over a very small time period.  I look forward to discussing my difficulties with my group tomorrow.  I have named this a "Philosophical" SOCS because I feel like this is a philosophical discussion, not a matter of curriculum or instruction.  I could imagine it being an instructional SOCS, but I guess I feel it is more about belief than practice.

Sunday, June 23, 2013

Arons 1.1-1.12 etc

SOCS - I
After reading the first few sections of Arons "Teaching Introductory Physics" I am feeling pretty good about what I have been doing in my class.  In one instance he talks about requiring students to tell the story about what 2.3 g/cm^3 means.  This is a standard practice for me.  I still think I can get better at leading students as a group to ask these same questions of each other, but I feel like I have at least recognized that there is a need for this verbal reasoning.  Now I just need to improve at leading/guiding the students to their own revelations.

Friday, June 21, 2013

SOCS-I The extended cut

"How We Teach and How Students Learn" (McDermott)
After reading this article, I am resolved to improve my teaching practices.  I can think of times during the year where I have worked to move away from direct instruction, and I have spent a lot of time discussing the types of situations described in the article.  For instance, the discussion on the brightness of light bulbs resonated with me.  I spent some time, after working through Kirchhoff's Rules,Ohm's Law, and graphing the current as a function of the voltage across a resistor and across a light bulb, discussing specifically the brightness of a light bulb.  In particular, I think it is difficult to describe what it is that makes a light bulb bright.  Is it the current through the bulb, or the voltage across it?  It is pretty clear, based solely on practical experience, that a 100W bulb is brighter than a 40W bulb in the home, but how does that relate to a set up in our lab.  I think the brightness of a light bulb is a complicated topic- perhaps more complicated than this article claims it is.  There are so many assumptions made in the typical questions that aren't necessarily obvious or true.  For instance, it is always assumed that the power rating of each bulb is the same, and that the resistance of the bulbs will be unchanged as the bulbs are added, removed or their connections are changed.  So, we talk about these sorts of things in my class, but gaining a good conceptual understanding of the brightnesses of bulbs in circuits is actually VERY difficult, and I am sure I do not have a clear model.

Now, I can answer the questions as long as I am willing to go along with the aforementioned assumptions, but I feel empty here-like I was "taught to the test."  As my students and I walk through our conversation on this topic, I feel like I am teaching to some future test for them (not mine.)  But I do wonder why the teachers at large seem to be in agreement that determining the brightness of a light bulb is somehow simpler or at least more approachable than finding the power dissipated by a resistor.

Now to a light bulb question I can really get excited about, can anyone provide a reasonable and (here's the kicker) simple model to explain the brightness of a 40W bulb connected in series with a 100W bulb?  I think I can do it, but it is going to require me to pull out the big guns, and if my students and I got into that conversation, a good many of my students would be running for the door.  Determining the current in that circuit would be a nightmare.  I mean, what is the resistance of a 40W bulb... connected in series with a 100W bulb?  I dunno, the wattage, as stamped on the bulb describes the wattage when the bulb is connected to 120VAC.  That will not be the case when it is in series with a 40W bulb.  Anyway, I digress.

I look forward to developing methods in this workshop that will allow me to walk with my students through questions, explanations and model building such that they gain a stronger understanding of the concepts of physics.  I have spent a lot of time in recent years making sure my test and quiz questions are assessing the kind of thinking and learning I am interested in seeing in my students.  Now, I hope that this workshop will help me make sure that my students' experiences in my class will better develop the kind of thinking and understanding I am looking for on my assessments.  I made this a "Instructional" type SOCS because I feel like I need to work the way I approach topics, and the way I lead students toward the light without pointing it out to them.  The workshop has been modeling that wonderfully for me, and I am so excited to practice these methods more.

And seriously, if you have a model for my light bulb question, I would love to talk about it with you.


Thursday, June 20, 2013

SOCS-I FCI

I think the Force Concept Inventory Test clearly addresses the errors apparent when using "common sense."  I hope to help my students learn to reason using Newton's Laws more effectively.
(Force Concept Inventory  Hestenes, Wells, Swackhamer)

SOCS-P "Wherefore a science of teaching"

After reading this article, I plan to think more about the concrete versus formal thinking going on.  I hope to incorporate the concept of "programming" a student's long term memory.
(Wherefore a science of teaching Hestenes)

The FCI

So, I must admit, I was a bit of a delinquent student today.  I thought I had set up mail forwarding from my new gmail address for this blog and for this workshop.  I apparently failed to click the bubble for "forward mail to this address."  I had set up the address and verified it, but alas, no bubble.  So, while I knew there was supposed to be some FCI test coming along, when I had not received notice, I figured some other plans were afoot.  Anyway, this morning, when I logged on to gmail to check the address of the location of the meeting (in an email received prior to my supposed forwarding attempt) I noticed a few emails from Don.  One of which was, of course, the FCI test.  So I madly woke up my home computer to print the thing this morning, and irresponsibly took it on my way to class this morning.  Luckily I arrived safely, with the test completed, only to find out that it would play very little role in what we discussed today in class:-(

I guess we were supposed to write about how we felt taking the test today.  My feelings are probably a bit, if not significantly, different than they would be if I had taken the test as it was intended, calmly and peacefully in my kitchen while my two daughters run around me screaming joyfully and asking when I will go and play with them outside.  In any case, I felt completely confident in my results, though some of the "air resistance" problems caught me asking myself, do they want the "real" answer or the "in a perfect world with no air" answer.  I opted for the latter in all of my choices.  I also found myself thinking, gosh, I wonder how my kids would do on this test.  We certainly talk about all of these concepts, and while I have never seen this test, we would certainly discuss the correct answers to all of the questions on it in my class.  I still wonder though, how would my kids do.  Or, in effect, how have I done as an instructor.  The alums that come back to speak with me usually talk about how well prepared they were for college physics, which I take as some sign that I am not completely wasting their time while they are with me.  So, I think I am doing OK, but I am not confident about how my students would perform on this test.  I am not even confident about how those alums would fare.  So, I plan on doing a before and after test next year to see what affect I am having on their understanding of the topic of force.  I hope to get a better understanding of how I am doing as an instructor, and over time improve my students' understanding of the concept of force.

Lastly, after spending 20 minutes trying to find the appropriate answer key for the test, I determined that, even though I took this test while battling traffic on 696 and Woodward Ave.  I aced it!  I mean, I should ace it, I am a physics teacher for goodness sake, but still, I always worry with things like this.  As a teacher, it always helps the confidence to know the answers before you ask the questions.  In this case, I was flying blind.  100% on this inventory is a small victory, but one I can be proud of.

Thursday, June 13, 2013

Introduction

Hey Folks,

If you are here, you must be in the Modeling Physics Workshop at Oakland Schools this summer.  I figured a good first post would be to introduce myself.  I am Ben, and I teach at University Liggett School in Grosse Pointe Woods, MI.  It is a PK-12 grade secular private school that was founded in 1878.  I just finished my 11th year teaching exclusively physics there.  I am also a class dean, I am in charge of creating the schedule, and I act as the registrar in the upper school.  One of the gifts I have is total autonomy in my classroom.  This has allowed me to design a neat curriculum, and test out a bunch of new teaching methods in my 11 years.  I currently teach two junior level electives called "Light, Sound, and Waves" and "Classical Mechanics" a junior level honors physics class and two senior electives titled "Calculus-Based Mechanics" and "Electricity and Magnetism."  I am interested in meeting other physics teachers from southeast Michigan, as I am the only physics teacher at Liggett.  I attended Lake Forest College in Illinois, and have been the lucky recipient of loads of equipment and advice from my college professors there.  But, while I have had lots of experience, and I get help where I need it, I have not had a lot of interaction with other high school physics teachers.  I became interested in attending this workshop after speaking with Gary Abud of Grosse Pointe North High School.  He spoke very highly of this program, and it was clear that he was an energetic and capable teacher.  It was also clear that his students engaged in class in a different way than mine do.  We are currently undergoing a shift in focus with our curriculum at Liggett, and we are placing a heavy emphasis on student engagement and on making thinking visible in the classroom.  Our headmaster has written an academic paper outlining the curriculum, and he has named this new model the "Curriculum for Understanding."  This workshop seemed like the perfect fit for me in my current place in my career.  I look forward to meeting all of you.  See you next Thursday!