The First Day of School: Marshmallows and Spaghetti

I have used this as a first-day activity for several years. Students walk in, and sit in groups of three or four assigned for them. The groups are given a large marshmallow, 20 sticks of spaghetti, about a meter of masking tape, the same length of string, and a scissors.

Spaghetti, tape, string, marshmallow

In 18 minutes, each group is to use these materials to build a structure that supports the marshmallow. The highest structure wins. Below  are a couple of groups working on their structure.



The marshmallow must remain whole, and the structure may only be connected to the tabletop. That’s it. That’s the whole activity, almost. I project a countdown timer, walk around saying encouraging words, and call out the measurements at the end. We talk about what they did that worked, about how important it is for a group to work together, and how they might do better next time, knowing what they know now.  A successful structure looks like this:


Most of these kids have never built any kind of structure, or even thought about what it takes to build a structure.  Building a stable structure out of spaghetti is tough in 18 minutes, but the marshmallow adds another dimension. Once you place the marshmallow on top, most of the structures don’t stand, or they lean over until they are barely above the tabletop. It’s fun, it’s exciting, and there are lessons to be learned from it.

I pitch it to the kids as a “model” of what they will be doing in this class:

  • they will collaborate in groups, often groups not of their choosing
  • the groups will be given unfamiliar problems to solve with familiar tools
  • failure is expected along the path to solving unfamiliar problems
  • failing publicly is expected during class
  • I expect them to learn from failure
  • trying is valued, not just success
  • success comes when you jump right in, apply what you know, and work together.

I didn’t invent this activity.There exists at least one website, devoted to it. In the TED talk posted on the website, Tom Wujec emphasizes how the including the marshmallow from the start leads to success. This is worth stressing to students in the physics classroom, as well.

Afterwards, we usually do something more traditional, a spring lab, or a pendulum lab. Talking about rules and procedures can wait until later. Getting right to work is more important.

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TESS has no meat on her bones

There are structural and cultural problems with the Arkansas Department of Education’s newish Teacher Excellence and Support System (TESS), the system by which teachers are evaluated. TESS is not really going to change anything.

TESS is based on Charlotte Danielson’s “The Framework for Teaching” which attempts to break teaching down into a bunch of separate components that can be assessed by evaluators, i.e. school principals.TESS replaces “some type of checklist” that most Arkansas districts were using with a purportedly clear but pretty complicated rubric. As far as I know, all Arkansas principals and teachers have received training and a copy of Danielson’s book. I don’t have any major problems with the book or the rubric. Really, I thought they were okay, with some reservations.

But student learning is going to be improved by giving everybody a new rubric? Really?

The main structural problem with TESS is that it doesn’t fundamentally change who does what, and how they go about it. Teachers are evaluated by principals. Principals have an interest in making sure their school is orderly, their “customers” are happy, and that the school appears successful (School Report Cards and word-of-mouth). Principals are busy. They deal with lots of phone calls, hundreds of emails, cantankerous students, parents, and staff. It’s not a job I would want.Principals evaluate classrooms to make sure the teacher has established procedures, the students are compliant and understand their roles, and that the education process appears to be moving at a reasonable pace for the level of the students. Principals rarely have an interest in the depth of learning that goes on in the classroom. It’s not their fault. As I said, they are very busy. And the chances that they come into a particular teacher’s classroom up to speed on the content depend on what they taught and how long ago they taught it. Principals are likely not even the person who should be evaluating this area of learning. I teach physics. I have never had a principal evaluate me who wanted to discuss the details of how students learn physics content. Twenty-plus years of teaching and a principal has never discussed with me how students learn the content. The depth of student understanding is the important part. This is the part that bears deep thought and consideration. Not whether or not students know how they are supposed to ask to go to the bathroom. Okay, so I’ve never been particularly great at the rules and procedures part of teaching. And I concede that it makes everyone’s life easier when the rules and procedures run smoothly. But the impact on depth of understanding? Not so sure. This is a cultural problem. If the classroom appears orderly and students “engaged,” then the culture assumes that learning is happening. But deep learning is a tricky thing. I think all of us who went to school can relate to forgetting everything you studied immediately after the test. That is not the kind of learning I am after. Deep learning requires thought on the part of the teacher. This is where another viewpoint would be helpful.

Another structural problem is the “classroom cul-de-sac.” Teachers have no way to move up without getting out. Teaching is teaching whether it’s your fifth year or your thirtieth year. The only promotion is to become an administrator, and then you are no longer a teacher. Teaching can be a lot of fun, and a lot of us don’t want to give up that part. After a few years of teaching, if you’ve worked your way into an assignment that you like and a nice classroom, that is probably where you will be at retirement (caught in that cul-de-sac).

Assuming you are deemed competent, there are no institutional incentives for improvement in teaching skills, monetary or other (is this structural, cultural, or both?). There are personal incentives, of course, and many teachers work hard to improve even after long years of teaching, for no reason other than to gain greater job satisfaction. But teachers generally don’t get paid more or recognized in any way for doing a better job.  Sure, teachers are rated by principals, but those evaluations are private, don’t impact salary and promotions, and rarely result in a concerted, cooperative effort to improve a teacher’s skills, particularly if that teacher is already a veteran teacher.

Teachers should evaluate each other. Peer evaluation could accomplish at least two things: 1. Teachers would  be more likely to get direct, practical feedback on their lessons. 2. Instead of having the same job for an entire career, experienced teachers would encounter new challenges and feel that their expertise was benefitting greater numbers of students.

A couple of experienced teachers in each department /school could be given an extra planning period and designated evaluators, They could do the grunt work of evaluating their colleagues, and a principal could review their work and sign off on it. Certainly the principal could observe and evaluate the team themselves, as well. At least one of the teacher/evaluators should teach the same or a closely-related subject.Better if both did. The evaluation could be a collaborative process, focused on student learning. Ideally, it would be something like the Japanese education system’s Lesson Study. In a lesson study, groups of teachers watch each other teach the same subject in different ways. The group collaboratively develops a lesson that helps students understand a complex topic. Evaluators and evaluated could grow together and improve instruction, so that students develop the deep understanding of a subject that leads to success. And an evaluation instrument exists that could help teachers evaluate each other. It’s called the Reformed Teaching Observation Protocol. It’s not a replacement for TESS as an all-around evaluation, but it does look at whether what goes on in a classroom has the characteristics that have been shown to get students thinking more deeply.

Here’s another take on Danielson’s evaluation system.

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What should a kid get out of high school science?

Some friends asked me this question recently, and I gave a bad answer. In my bad answer I said something like “They should know some things. Some big ideas.” And I listed a few that came to mind, like conservation of energy. I don’t think there’s anything too terribly wrong with that idea, I just don’t think it’s enough. Students should know some “big ideas”, but also they should be able to do some science. This post is an attempt to give a better answer.

First, about the big ideas kids (and everybody) should know.  I’ve always liked the book Science Matters: Achieving Scientific Literacy by Hazen and Trefil. It’s still in print,25 years after I first read it, and still relevant.  It’s written for everybody. It’s engaging, and the prose has a sense of style. And it relays a good summary of the basic science concepts in every discipline; the big ideas a person should understand after a basic course in science  like astronomy, biology, chemistry, or physics. So read the book, or this one you can download for free, if you are really interested.

That said, here are a few big ideas I hope students leave school conversant in:

  1. atoms , since somebody else said it better, I quote: “all things are made of atoms—little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another.” R.P. Feynman Lectures on Physics
  2. some things we can calculate (“quantities”) are conserved. in a closed system, the amount never changes: matter, energy, momentum, angular momentum, charge
  3. the universe, galaxies, solar systems, stars, planets are continuously changing in ways that are both understood and mysterious
  4. the earth is the only living system known, and it is a system of interconnected parts, both living and non-living
  5. organisms evolve, and their evolution can be understood both through fossils and observing living things; there is a common chemical basis for all life
  6. at different scales (of space, time, and energy), different methods of investigation and description are needed
  7. scientific understanding is constantly changing. a community of scientists works together to create the current best understanding. there are still many unanswered questions and huge gaps in our understanding

Now, about the science students should do (influenced by/condensed from modeling instruction and by the College Board’s Advanced Placement Science Practices):

Scientists make observations. Observations in science are usually measurements. No measurement is perfect; there is a limit to what can be known by measurement. The limits keep changing as technology improves, but there will always be a limit. Students should be able to make accurate measurements with classroom equipment, and be able to describe the limits of those measurements. Experiments are situations we create in order to make very specific observations.

Students should be able to create an experiment, or critique the flaws in somebody else’s experiment. They should understand the limitations of an experiment and also recognize when an experiment could be performed to find an answer, or at least the beginnings of an answer to a scientific question.

Observations/measurements are described by patterns. This is one of the deepest big ideas in science: there are recognizable patterns in nature. Some patterns are easier to observe, some more difficult. Patterns can be described by mathematics. When we know enough about a pattern, we use math, words, graphs to describe a conceptual model that encapsulates what we know about the pattern. Students should be able to describe the patterns in measurements using mathematics. They should be able to generalize these descriptions to describe conceptual models about nature.

Scientists make claims that are evaluated on the basis of evidence. Students should be able to make and evaluate scientific claims.

What’s the balance here between learning ideas and doing science? Ideally, students would learn science by doing science, as in methods like Modeling instruction, Process-Oriented Guided Inquiry Learning, Problem-Based Learning, and other inquiry instruction.

This is a very idealistic discussion. Being science literate depends on having a good understanding of these concepts and practices. Most students, those who just go through the motions in school as we know it, are not going to have that understanding. This discussion also leaves out engineering practices and applications, something important in the Next Generation Science Standards (and likely the to-be-released Arkansas High School Frameworks). So, I think this is a better answer, but not THE answer. Comments?

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Good Intentions

The Board of Education of the state of Arkansas has recently released the descriptions of the new Next Generation Science Standards-inspired courses for high school, debuting 2017-2018:  Proposed High School Science Courses.

There are a lot of things to like in this plan. It is ambitious. It aims for a future where all students have some measure of competency in the ideas and practices of science and engineering. It incorporates earth and space science objectives at all levels of 6-12 science. And the state will demand that all students take three years of high school science. Under the old “Smart Core” plan, only students who wanted to qualify for the Arkansas Academic Challenge Scholarship had to take three years of science. The NGSS-inspired revised Arkansas frameworks are likely to be much better than the old frameworks, which were heavy on facts to memorize and equations to manipulate, but light on understanding.

There are some significant challenges to this plan. The biggest one might be that every student is going to take “Principles of Chemistry and Physics.” There may be enough physics-certified teachers in Arkansas to accomplish this plan, but I really doubt that there are enough physics-savvy teachers in the state to carry it out. Physics certification is a low bar. Basically, anyone with a degree (a degree, not a degree in science) who can pass the Praxis in a subject can be certified to teach that subject. The Praxis, in my opinion, is not a test that demands deep understanding of the subject. Most teachers in this situation (forced to teach physics without the expertise, desire, or tools) will fall back on memorization, equation manipulation, or reduce the physics content in favor of the chemistry content.

Another challenge is the culture and climate around public education in the state of Arkansas. Most parents and students like the idea of students being college-ready, but their vision of college-ready does not include pushing students to understand and practice science. If students are asked to think, question, and understand, many parents and students will push back, and the pressure on teachers to revert to the status quo will be extreme.

Changing the entire system of Arkansas science education at once is a huge challenge. It’s going to require the cooperation and understanding of parents, students, teachers, and administrators. I hope there is an exceptional plan in place for educating everyone involved about the new frameworks. And more importantly, a plan providing professional development for all those who will be forced to teach science areas they are uncomfortable with. Unfortunately, some of my fellow teachers treat professional development as just a hoop to jump through, and choose to gain nothing from it. A two-day workshop is not going to be enough to change their minds about the importance of teaching for student understanding, or to provide an understanding of physics concepts.

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Using Tasks Inspired by Physics Education Research

Below are my thoughts on the Tasks Inspired by Physics Education Research (TIPERS).
These are really excellent tools to promote discussion in your physics class, no matter what the level. I strongly recommend buying one or more of these books. By the way, a lot of hard work by physics teachers like yourselves went into these books, and the authors are not making large amounts of money from them. So, if you meet one of the authors, thank them.

In my opinion, if you are only going to buy one of these books, you should get the “Sensemaking Tasks” book (the one with the blue cover). It has the widest range of different types of tasks and content. The Electricity and Magnetism Tasks book seems to be intended for Calculus-based physics courses like AP Physics C, Electricity and Magnetism. Many of the tasks in this book are very challenging. The Ranking Tasks book and the Newtonian TIPERS are both very good and very useful for both Physics C and Physics 1-2 (Newtonian TIPERS less so for Physics 2, of course).

TIPERS present a scenario that may be a familiar lab or “real-life” experience, often with a diagram and several different but similar alternative scenarios. Students are asked to do various things, rank the scenarios, find contradictions in student “analysis” of the scenarios, or simply explain something using physics. Although numbers may be given for physical quantities, TIPERS are generally not answered through calculation, and rarely are enough numbers given that students could plug numbers into an equation to find answers. Some TIPERS may be answered with little to no mathematic reasoning, and are more conceptual than mathematical. Others are very much easier if you reason proportionally using the equation, even though you don’t have complete information on all of the variables given in the task.

I generally use TIPERs with a conceptual basis early in a unit. I pass the task out, ask student to complete it silently and individually. This usually takes 5-10 minutes. After everyone has completed the task, including explaining their reasoning (a particularly important step), students discuss with their group or neighbors for an additional 5-10 minutes. When the groups have had a chance to reach consensus, I ask one or more groups to present their answers to the class, and the whole class tries to reach a consensus. I have been walking around talking to the groups, so I can choose to pick a group with the correct answer, or to pick a group with flawed reasoning but an interesting explanation for their reasoning.

I usually follow the same procedure with the more mathematical TIPERS, except that I wait until after students understand the equations to use them. It is often possible to answer these conceptually, using proportional reasoning but not an equation, but this is often a bit tortuous. It may take a little experience before you get a feel for the best time to use a particular TIPER, but once you discover that moment, you will probably want to use it every year in the same way. I usually only give one or two TIPERs per class meeting, and I don’t use them every class meeting. At this rate, students seem to enjoy them, and the discussions have been very productive. I insist on students writing complete answers, and sometimes take up the papers for a “participation” grade. No writing, no grade. I think this type of practice is especially useful for AP Physics 1 and 2, with the increased writing demands of their exams.

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Standards-Based Quizzing

This year in AP Physics 1 I’ve made a step towards Standards-Based Grading. I know I am several years behind the curve on this, but I am glad that I finally decided to make it happen. The slower pace of AP Physics 1 has made a big difference; I don’t see how I could be doing this in AP Physics B.

Over the summer, Tiffany Taylor of Rogers Heritage High and I worked to institute SBG, based largely on Frank Noschese’s excellent blog post, Keep It Simple Standards-Based Grading. I started with standards that other people (Frank Noschese, Mark Hammond on an older website) had published on their websites, based on the 9 modeling units that are presented at most modeling physics workshops.

Here’s a summary of differences between this year and last year:

Last year’s quiz questions – tailored after an AP exam, with difficult questions mixing topics. Usually two or three per unit. Quizzes were 20% of the grade. For most students quizzes lowered your grade and it was difficult to study for them or do consistently well.

This year’s quiz questions– frequent and straightforward, with a standard associated with each question. Each standard graded on a simple scale (2=I think you showed me that you understand the standard; 1=You seem to understand part of the standard, but not all of it; 0=I see no evidence that you understand the standard, or I see some evidence that you understand part of the standard but other evidence that you misunderstand part of the standard). Students can redo quiz questions if they have not passed the standard. This will result in  a higher grade, if they pass more standards. They can’t go down in their grade, unless they abuse the system repeatedly by not preparing for retakes of standards quizzes. Quizzes are now 35% of the grade, equal to tests.  Intended consequence: students know what they are quizzed on. Students prepare appropriately. Success rate? I think it is working for many students.

Last year’s tests – students who failed could take an alternate version, after studying with me. Something of a nightmare, and limited success for many students. They scored the same or lower, even after studying with me. A few did improve greatly and worked their way out of the fail, study, take a retest, system. Tests were 50% of the grade.

This year’s tests – you cannot retake a test. Tests are 35% of the grade, equal to standards quizzes. Thus, the primary preparation for the tests is equal in value to the tests themselves. This takes some pressure off of the students, and seems fairer to me. Intended consequence: My life is much more sane. It is much easier to write, reteach, give, and grade a short, straightforward quiz. My tests are like mini-AP tests, and some students were so far behind that studying the failed test was too big a task for them at that time. Studying standards quizzes one standard at a time breaks it down to a task they can manage.


I am keeping track of standards in a spreadsheet. The grading formula is this

Your Grade  = 50 + (Your Standards Score)/(Total # of Standards)

So, a student who averages a 1 on all standards has a 75% on quizzes. This seems much higher than they might have with points -remember, they are not getting correct answers on anything, they are just showing me they understand part of the process. All 2s would be a 100 average. For that, the student must be getting correct answers and showing that they understand all of the process.  .  .

The students are supposed to keep track of their progress, and they can apply to redo standards at our A&E (somewhat unstructured) time using a google form. Since we are on block scheduling, I am having some concerns about sharing quizzes. I have to write a lot of versions and keep them different enough so that the next day’s classes don’t know EXACTLY what’s on the quiz. This is going okay, but could go better (I suspect some students of cheating, in other words).

More updates on this later.

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Bare wires

In the last couple of years, I have made good use of the “bare wire” lab for electric potential difference. I first learned a version of this lab in the Modeling curriculum for electricity and magnetism. In this activity, students measure the potential difference of bare wires connected to a battery pack, but not connected to anything else. Lab2_Quiz_Quest1

This is extremely helpful in developing the idea that a wire can have zero potential difference along its length. And in developing the idea of potential difference being a difference between two different points.

Then, students connect a long bulb and a round bulb to the battery and repeat their measurements.


Finally, they make a graph of potential versus position.

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