Monthly Archives: September 2010

Letting Students Teach

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.

Targets Calendars

One goal that my team has for this year is to help students become more responsible for managing their own learning. One way we do this is to encourage them to track the development of their understanding on targets calendars. Targets calendars (i.e., standards calendars) enumerate the targets (standards) for the current unit and associate targets with specific days, activities, and homework assignments. The targets calendars for my General Physics class and Enriched (Honors) Physics class are a bit different due to the different structure of each course.

In General Physics, there are weekly quizzes and each target is assessed for three consecutive weeks (the 1st, 2nd, 3rd columns). The best two of three scores (on a 1-4 scale) comprise the overall score (the Overall column).

In Enriched Physics, there is only one assessment for a target in class (the A1 column). We encourage students to perform their own self assessment in preparation for this assessment (the SA column). If a student doesn’t demonstrate mastery of the target, they have a second opportunity to do so outside of class (the A2 column). However, they are first encouraged to perform additional practice and seek assistance before this second attempt. Again, we encourage them to self assess before the second attempt (column A2P).

Our targets need refinement but we are improving them each year. Hopefully, if interested, you can adapt the structure to your classes. Leave a comment if you have links to your own organizers that help your students manage their learning.



General Physics Syllabus

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:


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]( and am trying to make it better.)

Measurement Uncertainty Activity

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.