Category Archives: teaching

STEM Talk at NI

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Yesterday, I had the honor of presenting my experiences this past summer working on the Fermilab Holometer as well as my perspectives on STEM education at the high school level at National Instruments. Since my contribution to the Holometer project used National Instruments products and my family was vacationing in Austin, Texas, I offered to visit and share my experiences. I was a bit surprised when I was also asked to share my perspectives on STEM education in high school.

My presentation about the Holometer was pretty much the same as the one I gave the [Global Physics Department](http://globalphysicsdept.posterous.com/geoff-schmit-on-research-for-hs-teachers). (I’ve [written several posts](https://pedagoguepadawan.net/holometer) about the Holometer.) I added more technical details on the NI products involved and how the signal analysis was performed to better match the audience.

At first, I didn’t feel qualified to address National Instruments employees, who work for a company that are amazing supporters of STEM in K-12 with their efforts with FIRST and LEGO. As a result, I started my presentation with disclaimers:

* I do not have a master’s degree in STEM education
* I am not a STEM education expert
* I have not attended conferences and workshops in STEM education
* I have taught at a one high school for five years

However, once I sat down and started thinking about what I would share, I realized that I, like most physics teachers, am qualified to at least share my perspective because:

every morning I get up and try to inspire students in science, technology, engineering, and mathematics by leveraging my experience as an engineer, an interviewer, a supervisor, and a teacher.

In my case, I specifically left National Instruments and software development to become a physics teacher to make some small contribution by inspiring students to pursue studies and careers in STEM-related fields.

I structured my presentation around three high-level themes which I elaborated with photos, videos, and stories:

**Inspire Students with Experiences**

I shared that few students are inspired because of something they only read or hear or see; they are inspired by their experience doing it. I shared the experiences of my FIRST Robotics Team, Science Olympiad Team, and Physics Club. Physics Club is an after school, student-driven, low-commitment group that allows all students opportunities to play, inquire, create, share, and explore. I shared our past experiences with [near-space ballooning](https://pedagoguepadawan.net/60/nearspaceballoon/) and the [ping pong ball cannon](https://pedagoguepadawan.net/157/pingpongballcannon/). The second theme is:

**Inspire Younger Students with Older Students**

The main ideas for this theme are that students respond best to other students and students can loose interest in science during middle school. To address this, Physics Club and the FIRST Robotics Team perform outreach activities where younger students see projects done by the older students and build their own smaller-scale projects with the assistance of older students. The third theme is:

**Inspire the other 98% in the Classroom**

I was somewhat disappointed when I realized that all my efforts with FIRST Robotics, Science Olympiad, and Physics Club only involve 2% of the students at my school. I shared that this is a significant challenge but the most important theme. Many changes to a traditional classroom are required to inspire students about STEM:

* Change Perceptions
* Change Mindset
* Change Pedagogy
* Change Culture

I shared the importance of bring professionals into the classroom to share their experience and helping students appreciate that science is an active process done by real people. Despite significant local press about standards-based assessment and reporting, I shared how critical it is in my classrooms. I talked about Modeling Instruction, guided inquiry, project-based learning, and Project Lead the Way.

At the end, I felt compelled to take advantage of this opportunity to encourage those in attendance to help inspire students about STEM. I charged them to:

* Be Aware
* Promote Reform
* Provide Support

I was honestly surprised at the level of interest in my presentation based on the attendance and the number of positive comments afterward. So, for those of you like me who are career changers, if the opportunity presents itself, share your experiences as a teacher with your former colleagues. We may gain more allies in the challenges that we face everyday.

Honors Physics Ãœber Review Problem

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Honestly, I never look forward to reviewing before exams. We have a dedicated review day at our school and I have never found it particularly engaging or effective for students. A few students have a list of specific questions to ask, and they benefit from the answers and discussions, but many do not.

This year, in Honors Physics, the calendar was such that we ended up having three days to review for the semester exam. My colleague had a great idea: create the Ãœber Physics problem (also known as the problem that never ends). Our goal was to review every one of our twelve [more-challenging standards](https://pedagoguepadawan.net/119/honorsphysicsstandards/). We brainstormed on a sequence of events that could be woven into a story. At the start of class, we introduced the story for that day and then left students to work through the problems with each other, ask questions about needed information, and check answers. The next day, we would summarize the previous day’s events, associated standards, and solutions before introducing the next “chapter” of the story. For the past three days, students were the most engaged during review that I have ever witnessed. They were interested in the story and excited by what the next “chapter” might bring. These problems were challenging which I believe also contributed to the interest.

Some simplifying assumptions were made but the students weren’t too critical. Unfortunately, I made a calculation error that affected the third day’s problems. When the error was corrected, the final coefficient of friction was ridiculous. I’ll have to adjust the story if I do this again next year.

While much of the story was conveyed verbally, I’ll share the rudimentary pictures that I drew and some of the specified variables. Each page corresponds to one day’s part of the story. The perspective of the diagram changes at times to show the necessary information. The answers are written in green or red and were provided one day after that part of the story was presented.

Download (PDF, 315KB)

Next-Time Questions

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One of my favorite resources for developing conceptual understanding of physics are Paul Hewitt’s Next-Time Questions. Older ones are [hosted by Arbor Scientific](http://www.arborsci.com/Labs/CP_NTQ.aspx) and every month a new one is published in [The Physics Teacher](http://tpt.aapt.org/).

These questions often appear deceptively simple. However, a student’s first impression is often incorrect. I find that these are a great way to discuss and refine preconceptions. These questions are intended to be presented during one class and not discussed until the next. I always have students who are so excited to share their answer they are practically bouncing in their seats. I have to remind them that these are “next-time” questions and, therefore, we will discuss them the next-time we meet. I encourage them to discuss them with their friends over lunch or after school.

Hewitt implores us to use them as he intends:


Although these are copyrighted, teachers are free to download any or all of them for sharing with their students. But please, DO NOT show the answers to these in the same class period where the question is posed!!! Do not use these as quickie quizzes with short wait times in your lecture. Taking this easy and careless route misses your opportunity for increased student learning to occur. In my experience students have benefited by the discussions, and sometimes arguments, about answers to many of these questions. When they’d ask for early “official” answers, I’d tell them to confer with friends. When friends weren’t helpful, I’d suggest they seek new friends! It is in such discussions that learning takes place.

Here is one that I recently used during the Balanced Force Particle Model unit.

Next-Time Question

The next time my class met, the discussion of this question consumed almost the entire class time. The discussion started with a review that the forces must be balanced since the book is at rest (the special kind of constant velocity where the velocity is zero). We practiced drawing the free-body diagram for the book which was a good review of the force of friction and the normal force. We were just beginning to explore vector components, and this was a great introduction since the force from the woman’s hand is directly both upward and to the right. We then debated if the force of friction should be directed upward or downward. Students had valid arguments for each. Another student asked if there was a force of friction at all. Eventually, we drew three different free-body diagrams for the cases where there is no friction, where there is friction directed upward, and where there is friction directed downward. A fantastic discussion all centered around a single drawing and simple question.

Some time ago, I reviewed every next-time question, downloaded those that aligned with concepts we cover, and copied them into unit folders so I would remember to use them when the time was appropriate. Now, I just review each month’s next-time question in The Physics Teacher and file it appropriately.

Give one a try in class. I think you and your students will love it.

The Preconception Eliciting Tennis Ball

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After investigating the motion of a falling object, I ask my students to draw position vs. time, velocity vs. time, and acceleration vs. time graphs of a ball that is thrown upward and then caught at the same height. As I walk around the room, most students have the position vs. time graph correct but struggle with the velocity vs. time and the acceleration vs. time graphs. For those students that struggle, the most common sketch of the velocity vs. time graph is a ‘V’ rather than a straight line with a negative slope. They then struggle to reconcile an acceleration vs. time graph with this V-shaped velocity vs. time graph.

I then model how I reason through these types of conceptual problems. I hold the tennis ball in my hand and ask, “Immediately after I release the ball, in which direction is it moving?” (They confidently say “up.”) I ask, “Immediately after I release the ball, is it moving fast or slow?” (They confidently say “fast.”) I then encourage them to plot that point on their velocity vs. time graph. I then ask while climbing on top of a lab stool, “As the ball travels upwards, how does its velocity change?” (They confidently say “it slows.”) While holding the ball near the ceiling, I ask, “When the ball is at its peak, what is its velocity?” (They confidently say “zero!”)

I now expose their preconception by immediately asking, “What is its acceleration?” (The answers are split between “9.8 m/s/s” and “zero!” depending on the class) I keep the ball near the ceiling and ask one of the students who enthusiastically answered “zero!”, “If its acceleration is zero and its velocity is zero, what would happen to the ball?” After some thought, the student realizes that the ball wouldn’t fall. I then release the ball and it sticks to the ceiling.

This demonstration appears to be sufficiently memorable due to its humor or unexpected outcome, that students can replace their preconception about the acceleration of an object at its peak. After some laughs, a reference to all the balls that are not suspended in midair over the tennis courts, and an [xkcd comic](http://xkcd.com/942/), I continue demonstrating how I reason through the creation of velocity vs. time graphs. I ask the final part, “When the ball is about to be caught, in which direction is it moving?” and “Is it moving fast or slow?” I encourage them to plot this final point and then they have replaced the V-shaped graph with the proper velocity vs. time graph. The slope of their corrected velocity vs. time graph confirms that the acceleration of the ball must remain constant. The tennis ball spends the rest of the class period stuck to the blackboard.

We have a group of Physics teachers that meet at an area school monthly and share ideas. I learned this demo from a great Physics teacher at one of these meetings. He has practiced enough where he can throw the tennis ball and have it stick. He showed us how to modify a tennis ball:

tennis ball demo materials
*Materials: Neodymium magnets, tennis ball, utility knife, hot glue gun.*

magnet glued inside tennis ball
*Slice the tennis ball, squirt in a bunch of hot glue, and stick in the magnet.*

tennis ball sealed
*Seal the slit in the tennis ball and let harden.*

tennis ball experiencing no acceleration
*Stick the tennis ball on the ceiling!*

Circuit Sudoku

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During this semester, which mostly consists of electricity and magnetism, I’ve really started to appreciate that the content is the vehicle through which students develop problem solving, critical thinking, and long-chains of reasoning. Later I will write how electrostatics is a great start to developing these long-chains of reasoning before we really exercise that skill with circuits. While not as challenging, circuit analysis is a good application of problem solving skills that illustrates how organizing data can make it much easier to solve problems.

We’ve started calling this problem-solving approach Circuit Sodoku.

The technique has evolved over the years based on input by teachers and students. I expect that it is similar to techniques used elsewhere. Regardless, my students find it very helpful when analyzing complex circuits.

At the heart of the technique is the V = IR table which has the following elements described below and illustrated in the photo of a group’s whiteboard:
* three columns: V (voltage), I (current), and R (resistance)
* the first row represents the equivalent circuit which specifies the voltage of the source, the current through the source, and the equivalent resistance of the circuit.
* each subsequent row corresponds to a resistor in the circuit

Students follow these steps to analyze circuits:
1. solve for the equivalent resistance (redrawing the circuit after each step, if necessary)
2. calculate the current through the supply based on the supply’s voltage and equivalent resistance
3. look for resistors in series or parallel with the source and update the table with the current or voltage associated with that resistor
4. apply the loop rule and junction rule to complete blanks in the table

Whenever two of the three columns for a row are completed, students use Ohm’s Law to calculate the third value.

Here’s an example:

circuit whiteboard

Just to be clear, Circuit Sodoku is not the heart of our circuits unit. Before we start analyzing circuits in this manner, we have spent weeks developing our conceptual understanding of circuits using the [CASTLE curriculum](http://www.pasco.com/featured-products/castle/page_3.cfm). Many students find Circuit Sodoku a welcome break at the end of the unit.

Circuit Sodoku used to be the most challenging problem-solving application of my circuit unit. Now it is the easiest. I’m pleased we are focusing more on developing these essential problem solving, critical thinking, and long-chains of reasoning skills.

Einstein Day

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Last week, I got fed up and couldn’t take it anymore.

I’m fortunate that many of my students are really curious about science and ask fantastic questions.

Sometimes these questions are directly related to the topic that we are investigating, and we discuss them immediately.

Sometimes these questions are unrelated to the topic at hand but are of a limited scope and can be discussed and as a short tangent to the “plan” for the day.

Sometimes these questions are directly related to a topic that we will study in the future, and we table them until that time.

Sometimes these questions are unrelated to anything we study, are not quickly discussed, and are fantastically engaging. Often these questions are in the area of modern physics. Since we don’t study anything in my regular or honors physics courses that was discovered within the last century, these topics are not part of the curriculum. (Yes, I’m working to address this.) An answer of, “we study that in Advanced Physics” is unsatisfying since most of my students won’t take a third semester of physics. Our curriculum, especially in honors physics, is so aggressive that we really don’t have the flexibility to chase down these fantastic tangents.

So, last week, while discussing the doppler effect in the context of sound, a student asked what would happen if a car traveling at the speed of light turned on its headlights? Would the doppler effect apply in some way? Wow. The other students were immediately engaged and started proposing ideas and more questions. I couldn’t bring myself to once again say, “we study that in Advanced Physics.” Instead, I got a huge sticky note, slapped it on the wall, titled it, “Physics Questions,” and added the question. I declared that we would capture fantastic questions like this and dedicate time later in the semester to have a series of short presentations and discussions to explore them. Students can research questions in which they are interested and I’ll take a few too.

They asked when we would do this. I Googled for Einstein’s birthday. March 14th. Someone remarked, “hey, that’s pi day!” Serendipity.

Anyone care to join us?

Electronic Whiteboards

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Yesterday, I finally had the opportunity to try something that I have been wanting to do for over a year: electronic whiteboards.

Last year, we were the fortunate recipients an an HP Innovation in Education grant which included a classroom set of tablets (we never had tablets before). I immediately thought of having students prepare traditional Modeling whiteboards on the tablets and project their “whiteboards” on a screen as they present them. I encountered two roadblocks. One, my classroom has a front “lecture” area with individual student desks and a screen and LCD projector and a back “lab” area with lab tables. We prepare and present whiteboards in the lab area and hang the whiteboards from two S-hooks tied to the ceiling. I wanted to continue to prepare and present electronic whiteboards in this lab area which would require obtaining a new projector. We found an extra projector which was installed near the end of last year. The second roadblock was that I didn’t want to incur the overhead of students physically connecting a VGA cable to their group’s tablet in order to present. I wanted to seamlessly be able to switch between laptops. This just recently become a reality as the projector was connected to the network.

Electronic whiteboards were fantastic. Especially considering that we had never attempted them before and the process was new to the students and me. We noted several advantages to electronic whiteboards over traditional whiteboards:

* We’re not as tempted to rush through presentations as we near the end of class. If we don’t get to a whiteboard in one class, we can display it the next day. Today, we quickly picked up where we left off at the end of class yesterday. This is significant since I only have ten whiteboards in my classroom in which eight classes are taught every day. It is not always feasible to save a whiteboard from one day to the next. (Yes, the irony of having a classroom set of tablets but not a whiteboard per group is not lost on me.)
* Whiteboards are exported as PDF files and uploaded to the class website on [Schoology](http://schoology.com/). Students can view whiteboards outside of class if they are absent or if they want to review them again. Students can also comment on whiteboards posted on the website so the conversation can extend beyond the classroom. Students commented on this advantage much more than the others.
* Whiteboards appear to have more detail and yet are easier to read than traditional whiteboards. If more room is required, OneNote (which is the application in which we’re drawing our whiteboards) simply grows the page. This encourages groups not to artificially limit themselves to a 2’x3′ whiteboard. Furthermore, the whiteboard is projected on a large screen. If a group writes too small, they can zoom in and scroll around during the presentation. In addition, none of the lines look like they are drawn with dried out whiteboard markers!

whiteboard.jpg

I’ve only noticed one potential disadvantage. The physical tablet screen is smaller than a physical whiteboard. Groups still huddled around the tablet like they would a whiteboard, but it is not as large an object around which to gather. Also, only one student can write on the tablet at a time while occasionally two students will be writing on the same whiteboard at the same time. So, I’ll have to keep an eye on this and make sure that the group collaboration during whiteboard preparation doesn’t suffer.

We’ll definitely try this again. I expect that it will even go smoother since students are now familiar with the tablets, OneNote, and how to connect wirelessly to the projector. If anyone has tried something similar and can offer some tips, please share!

Halloween Physics

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There is a tradition at my school of physics and chemistry classes having a day of science-related demos on Halloween (or the closest school day). We share and discuss a wide variety of demonstrations with the students that relate to topics they have already studied, topics they will be studying, or just cool stuff that, for whatever reason, we won’t study.

One of my favorite demonstrations involves a PVC pipe, a ping pong ball, a soda can, and a vacuum pump. The ping pong ball is inserted into the PVC pipe and both ends of the PVC pipe are sealed with mylar (the shiny material of some helium balloons) and PVC couplings. The vacuum pump then evacuates the PVC pipe. Once evacuated as much as possible, a knife tip breaks the seal at one end of the PVC pipe and the ping pong ball is pushed out the other end at an incredible high speed. Last year, we captured the result with a high-speed video camera (1000 fps):

This demo provides a great shared experience to later relate to almost any area of mechanics. I can use it as an example for the work-energy theorem with my regular physics class, fluids with my advanced physics class, or challenge the AP C class to solve for the force on the ping pong ball given the pressure applied to the hemisphere. Plus, we now have a whole collection of decimated soda cans on display!

Letting Students Teach

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I’m really making an effort this year to have a much greater percentage of class time spent with students learning together in small groups as they solve physics problems rather than me solving problems on the board. I’ll still model how to solve certain types of problem to demonstrate problem solving best practices, but I’ve observed much more effective learning when students are working through problems with a small group of peers rather than copying what I’m writing. However, what I don’t want to happen is for one student in a group to understand how to solve the problem and simply tell everyone else in the group the solution such that they just copy what she writes.

I realized that this was an opportunity for some coaching. I requested that, while groups work on solutions to the problems, they refrain from simply telling each other the answers. Since we were working on drawing graphs of motion (position vs. time and velocity vs. time) from descriptions, I asked that the students confident of their answers instead describe the motion graphed by the other students. When the students hears the description of the motion that doesn’t match their intended descriptions, how to correct the graph may be clear. It wasn’t too much of a stretch to have students facilitate their group’s discussion in this manner since students are slowly becoming familiar with the socratic questioning during whiteboarding and are already used to the fact that I respond to almost every question with one or more questions of my own.

As I walked around the room, I witnessed a dozen teachers effectively giving individual attention and support to a dozen students.

No one asked me question.

Feynman the Teacher

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I started reading *Six Easy Pieces* by Richard Feynman today. I absolutely loved his autobiographical collection of stories: *Surely You’re Joking, Mr. Feynman!* and *What Do You Care What Other People Think?*. However, I wanted to read something that would give me more insight into Feynman the Teacher. So, I started reading *Six Easy Pieces* since I don’t have time to read the entire *Lectures on Physics* this summer. I’m just getting started, but I found a couple of great quotes in the introductions. Here’s a note he wrote in 1952:

First figure out why you want the students to learn the subject and what you want them to know, and the method will result more or less by common sense.

Of course what is common sense for Feynman probably isn’t for the rest of us. Given his reputation as a showman and brilliant lecturer, I find his “solution to the problem of education” particularly insightful:

I think, however, that there isn’t any solution to this problem of education other than to realize that the best teaching can be done only when there is a direct individual relationship between a student and a good teacher — a situation in which the student discusses the ideas, thinks about the things, and talks about the things. It’s impossible to learn very much by simply sitting in a lecture, or even by simply doing problems that are assigned.

My summer inspiration.