Tag Archives: physics

Adjustments for Second Semester

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Our team of four physics teachers recently convened to reflect on the first semester of standards-based assessment and reporting in Regular Physics. While two of us have been implementing SBAR in Honors Physics, this Fall Semester was the first for Regular Physics. There are many, many aspects of how we integrated our SBAR philosophy that we found beneficial. However, the primary focus of our meeting was to address those aspects that we felt could be improved.

**Assessing every standard for three consecutive weeks is not an effective use of time for most students.**

Every standard would be assessed on three consecutive quizzes which would take three weeks. The first quiz would assess the standard in a more conceptual and basic manner and the second in a more advanced and comprehensive fashion. In combination, they provided a good measure of a student’s understanding. The third quiz wasn’t necessary for most students since they had already demonstrated that they understood the standard. That precious class time could be used more productively.

We decided that we would eliminate the third in-class quiz and make it an optional outside-of-class quiz. Those students who needed an additional opportunity to demonstrate their understanding may take this third quiz. The third quiz will be advanced and comprehensive since a student’s score on it replaces their score on the first two quizzes. Based on prior experience, we picked a single day every week when these third quizzes will be offered before and after school. At a bare minimum, students are required to submit corrections to the first two quizzes before they earn the opportunity to take the third quiz. Students are encouraged to pursue much more substantial learning activities before taking the third quiz.

**The mapping of 1-4 to traditional percentages was problematic and inflated.**

Our mapping of the 1, 2, 3, 4 indicators, which are used on almost all assessments, to traditional percentages as required by our school’s gradebook had a few issues. Students and parents were concerned that a “4” didn’t map to a 100%. It is really hard to not focus on traditional grades when our grade book only presents traditional grades. At the other end, the traditional percentages assigned to 1s and 2s didn’t reflect that lack of understanding that they should. Personally, I found that some students who were really struggling to understand physics didn’t appreciate this fact because their grade was inflated due to the mapping (“I’m doing fine; I have a C”).

For the Spring Semester, we will map our 1, 2, 3, and 4 indicators to traditional percentages as follows: A 4 corresponds to a 100%; a 3, 85%; a 2, 65%; a 1, 50%.

**Too many standards.**

Despite warnings from the two of us with previous SBAR experience, we still defined too many standards for each unit. Several times, this resulted in too much class time spent assessing multiple targets that could have been effectively assessed in combination.

As we define the standards for our Spring Semester units we are trying to combine standards when possible. However, if standards are too broad, it is hard for students to clearly understand what they are expected to learn. Which leads us to the next aspect in need of improvement.

**Use consistent terminology to more clearly communicate with students, parents, other teachers, and administrators.**

Our school is in the process of creating a glossary of terms with common definitions to address this aspect that is in need of improvement. One especially egregious example concerns the use of the word “target.” Our school has a history of defining “target” as a student-understandable and demonstrable goal for a daily lesson. We have been using “target” as a synonym for standard which is much broader.

In the Spring Semester, we will call our standards “standards” and our daily goals “targets.” This will help, but not address the problem that a high-level standard may be too vague for students to clearly understand what they are expected to know. Next school year, I hope to associated several targets or objectives with each standard to provide a connection between specific learning goals and higher-level standards.

Most of us can’t imagine going back to teaching Regular Physics like we did last year. That alone is a great sign that we heading in the right direction. Thankfully, we were given time to reflect and adjust for the Spring Semester which now looks even more promising.

***Update: Fri Dec 17 00:28:05 CST 2010:***

I’ve scanned the above referenced [glossary of terms](https://pedagoguepadawan.net/wp-content/uploads/2010/12/sbg-glossary.pdf), which is still a draft document.

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.

General Physics Syllabus

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I’ve been intending to share my syllabi for my classes and finally made the time to do so for my General (regular) Physics class:

syllabus.pdf

If you trying to implement standards-based grading (SBG) in your classroom, you may find the approach taken by my team interesting. The structure that we created is based on how my colleague and I organized our Enriched (honors) Physics class last year when we first implemented SBG.

When communicating our SBG methodology to students, parents, and other teachers; I’ve found the categorization of activities into the two buckets of learning activities and summative assessments very effective. It helps make very clear the difference between learning and demonstrating understanding.

One more note, the conversion of the 1-4 grading scale to percentages is only done to work with the severely limited grading software that we have to use. I’m looking forward to a new software system next year that can support SBG. Hopefully, it works as well as SnapGrades, which I used last year.

(If the idea of homework as a learning activity and summative assessment nauseates you, I [share your feeling](https://pedagoguepadawan.net/11/igradehomework/) and am trying to make it better.)

Measurement Uncertainty Activity

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In previous years, my students have always struggled to really understand measurement uncertainty. Due to my background in the computer-based measurement and automation industry, I was always troubled that I didn’t do I better job helping them understand. So, this year, I developed a set of six activities to provide a hands-on way to practice applying the definitions as well as provide a context to discuss the complexities of measurement uncertainty. Each group investigated one of the activities and then whiteboarded and presented their results with the rest of the class. Each activity had the group determine the measurement uncertainty of a measuring device and calculate the maximum percent uncertainty of their measurements. However, each activity also had a deeper purpose that led to good class discussions during whiteboarding.

1. Measure the dimensions of a block with a ruler. Deeper purpose: calculate the percent uncertainty of the volume of the block.

2. Measure the width and length of the lab table with a modified meter stick (cm precision). Deeper purpose: how does having to make multiple measurements to measure the length affect the measurement uncertainty?

3. Measure the period of a pendulum with the wall clock. Deeper purpose: how does the percent uncertainty change if 2, 5, 10, or 20 oscillations of the pendulum are measured instead?

4. Measure the temperature of ice water and hot water with a digital temperature probe. Deeper purpose: is the percent uncertainty of the cold-water measurement actually greater than that of the hot-water measurement? How does measuring the temperature differ than all the other measurements (difference vs. absolute)?

5. Measure the time for a ball to drop from the table to floor and the ceiling to floor with a digital stopwatch. Deeper purpose: Are the measurement as precise as the measurement uncertainty of the digital stopwatch (1/100 of a second)?

6. Measure the speed of the cart on the track using a photogate connected to the computer. Deeper purpose: What does the computer actually measure? What determines the measurement uncertainty? Determining the actual uncertainty of a photogate connected to a laptop running Logger Pro via a LabPro is well beyond the scope of this course (although, in my Advanced Physics course, we figure it out). Still, students realizing that computer-based measurements don’t have infinite precision is an important lesson.

The class discussions that occurred while whiteboarding were fantastic and this year’s students have a much greater appreciation of measurement uncertainty than those of previous years.

I Grade Homework

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Last year, myself and a colleague jumped into the standards-based grading pool with both feet with our honors-level physics class. We appreciated that homework was for practice and should not be graded. I was very excited about this departure from the traditional model of checking homework every day and keeping track of completed homework and absences which wasted valuable class time.

At first, students attempted their homework as assigned. However, before too long, it was apparent that a vast majority of students were not attempting the homework problems before we were to whiteboard them in class. After one particularly ineffective whiteboard session, due to a vast majority of students being unprepared, I attempted to use that experience to illustrate the importance of using the homework problems as practice.

Why did this happen? Did we fail to explain our standards-based grading philosophy? No, I think students appreciated the importance of the learning activities. Students were engaged in learning activities such as labs even though they were not graded. Were the homework problems unnecessary busywork? No, this class moves at a fast pace and, for a vast majority of students, practice outside of class is essential. Students weren’t attempting just the problems they felt they needed to practice; they weren’t attempting any problems.

After this ineffective whiteboard session, a few students with whom I had stronger relationships made a point to talk to me about why they hadn’t attempted their homework. All of them said that they appreciated that they needed to practice these problems. All of them said that they knew that they wouldn’t be able to effectively whiteboard the problems without having at least attempted the homework. All of them knew that eventually they would need to practice in order to do well on the summative assessments. However, all of them also explained that not doing their homework was a conscious decision. They explained that they get home late due to soccer/marching band/play practice. They explained that they have more homework assigned then they can possibly complete in a night (another issue to address). If they don’t complete their math/social studies/other science homework, they lose points, their grade is impacted, their GPA is affected. They believe the only logical choice is not to do their physics homework.

**When other classes assign points to homework, overloaded students that are grade-centric won’t do homework that isn’t assigned points.**

What did we do? We started grading the homework the next semester. We reconciled this change by framing homework as both a learning activity and summative assessment. We continued to whiteboard homework problems (learning activity), but, by the end of the unit, students were required to submit their homework solutions via WebAssign (summative assessment). We used WebAssign since we were able to randomize the numerical values in otherwise identical problems. This allowed students to collaborate but not copy final values.

We haven’t satisfactorily solved the problem of homework. Our current approach is simply the best idea we have at the moment. Over time, this issue may be mitigated as more and more classes in our high school adopt standards-based grading and fewer and fewer teachers grade homework.

If you’ve encountered this problem and are taking another approach, please share! We can always make a change next semester!

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.

How Many Standards?

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When my colleague and I started our standards-based grading journey in the Fall of 2009, we started with a list of objectives defined years previously by a now retired teacher. Since our goal was to make minimal changes to the curriculum and focus on changing the methodology for the class, we decided to use these objectives as the starting point for our standards (which we refer to as “targets”).

What I quickly learned is that I needed to know exactly how I would provide multiple learning activities and multiple summative assessments for each and every standard. Our first unit had 26 standards! While several were lab-specific, that was way too many! We immediately appreciated the importance of defining fewer and more general standards.

How many standards are right for a unit; how many for a semester? I think the answer is different for every class, but after a year of experience, I’ve found that seven or eight standards of which one or two may be lab-specific works well for our honor-level physics class and students.

I just finished revising the standards for the upcoming Fall semester for this class. I ended up with about sixty standards for the semester. This is a fast-paced class and that is reflected in the number of standards. In comparison, my regular-level physics class will have a little more than half as many standards this Fall.

Am I completely satisfied with the number and granularity of the standards for the Fall semester? It’s definitely a step in the right direction, but, no, I’m not completely satisfied. I think I did the best I could balancing the tradeoff between a manageable number of standards from an assessment perspective and sufficiently specific standards such that students are clear on what they need to understand.

I’m not positive how I’m going to improve this aspect of the methodology, but I think the eventual solution is to move to a two-tier system. The top tier would consist of fewer, higher-level standards that are assessed and reported while being manageable. The second tier would contain many more specific sub-standards (“targets”) that students can readily understand.

Please feel free to leave a comment and share your approach for defining standards.