I haven’t posted in a month! Conference time.

Sorry guys, I have been super busy.  I am presenting work (in progress) at the SACS/NCS-AAPT meeting in Asheville, NC next week.  It is work I have been working on in collaboration with John Burk and Michael Schatz.  We are integrating computational modeling (via VPython) into the ASU modeling curriculum.  We have designed activities and assessments however I will be presenting mostly on the implementation.  If you are into this sort of thing and are going to the meeting you should definitely come see my talk.  I promise not to goof up too much!

Some Observations

It is approximately halfway through the semester and I have some observations.  I have spent a lot of time in class trying to emphasize what is important and drop the rest on the side of the road before I come into work.  I would like to say that these statements aren’t blanket statements.  Many of my students may not fit into any of these categories and just because they do doesn’t mean there is something wrong with them.  Here are my observations.

Many students still can’t recall Newton’s Laws.

Newton’s Laws are ridiculously important.  If the students can’t even recall Newton’s Laws than how can we expect them to understand anything else we talk about in this course?  At this point in the semester the students should at least be able to list them to me when I ask and many can’t.  Perhaps I haven’t been emphasizing how important Newton’s Laws are to force and motion (maybe it would be more clear to them if we had started the semester teaching Newton’s Laws instead of kinematics).

Many students have begun to not take the activities as seriously as they did at the beginning of the semester.

This is probably due to several reasons and I’ll mention one of them.  The grading scheme has consisted more so on participation than on accuracy of the written statements.  This is because I think that marking students down for writing the wrong answers on the page is not a viable solution that helps the student to learn.

The students are having a hard time seeing how the activities they are doing is helping them.

I have blogged before about how the undergraduate curriculum needs to include objectives that the students actually care about.  Objectives that their future employers actually care bout.  No one will ever care if these students can find the forces on a object resting on an incline plane.  This is not a calculus based course.  Physics majors don’t take this course.  So why are we teaching them like they are physics majors?  Why do we expect them to care?  Perhaps we should create a list of standards for the course (thank you Andy) which are also motivated.  Every standard will have next to it a reason why someone other than a physicist would care if the student can perform the skill or demonstrate mastery.

These are some things to think about between now and next semester.  I suppose I could always just talk about everything through the lens of Battlestar Galactica.

 

Flat Earth Lives!

On Friday the students took their first exam.  I recommended that we run an activity that was based on problem solving, group work, and that was just general fun on Monday to “give the students a break”.  The professor agreed to this and relinquished control of Monday to my whims.  I took a group activity that I knew about from a friend of mine (and former physics professor) and tweaked it a little.  The assignment is as follows:

You live on a planet that is always overcast.  The day begins with the sky becoming bright and ends with the sky becoming dark.  All shadows from natural light are diffuse and nondescript.  You have never seen the star your planet orbits nor the sky.  Modern technology abounds every where except the technology of flight does not exist.  Recently there has been great debate in the scientific centers of your society.  Is the planet flat or round?  Some scientists hypothesize that the planet is indeed round while others say that it is flat.

Odd tables are in the camp of scientists who believe the planet is flat but each table may have a difference of opinion.  Each table will create at least one experiment to show that the planet is flat.

Even tables are in the camp of scientists who believe the planet is round but each table may have a difference of opinion.  Each table will create at least one experiment to show that the planet is round.

After the hour is up each table will present their ideas to the forum of scientists.

The students took this assignment and ran with it.  I was really impressed.  They came up with solutions I had not thought of before.  One group designed an experiment using multiple lasers pointed skyward and then the distance between them would be measured.  If they are parallel than the world is flat, if they move away from each other the world is round.

Another group designed a study abroad program that had students traveling across the globe communicating with cellphones.  This broached a discussion about whether the technology would be appropriate because cellphones may use satellites (and satellites don’t exist).  The appropriate use of technology is always important to science.

One flat earth and one round earth group both came up with the same idea (using lasers across large distances and measuring how it varies from the surface) which started the conversation of scientists in different parts of the world working on the same ideas.

A flat earth group came up with firing a massed object at a high speed that would escape the planet’s gravitational pull on a round planet and land on the ground on a flat planet.  This produced intense discussion between all of the groups.  I hope everyone learned constructive criticism is good for science and life in general.

The 3rd round earth group figured out that if the planet was round the weight of an object should be the same at the same altitude anywhere on the planet.  They then showed that if the planet was flat then gravity would vary depending on how close you were to the center of mass.

All in all I thought this assignment was a great success.  I hope the students felt like they got something out of it.  I was very impressed with their ideas.

 

Battlestar Galactica Physics

Halfway through the lab on Wednesday I started getting questions from just about every table about what was going to be on the exam on Friday.  Since I didn’t write the exam I don’t exactly know what will be on it but I have a good idea what students should know for a first exam in introductory mechanics.

Now let me stop right there and say that I LOVE Battlestar Galactica.  I think it is probably one of the greatest TV shows I have ever seen.  I love the characters, the plot, the special effects, the music.  It was the first time I had ever gone to dragon*con and gushed over famous people (besides the MST3k guys).  So when I talk about Battlestar Galactica I get a little more excited than usual.

So I let the students ask me questions that they think might be important.  The common factor in many of them is what did they need to know to be able to answer the questions on the test.   I answered by posing the following question to students.

I am Commander Adama and I am guiding the Battlestar Galactica on a fateful journey from the original 12 colonies to the fabled Earth.  We are in deep space far from any planets or stars and traveling at a constant velocity.  What is the net force on the mighty Battlestar Galactica?

Maybe it was the way the question was posed but I found that many students right before the exam on Force and motion couldn’t tell me that the net force on an object moving at a constant velocity is zero.  So we talked about it and they did the customary student “remembering” that indeed the net force must be zero with no change in velocity.

I asked another question which was basically the same question.

I am Starbuck piloting my Viper fighter out the side of the Battlestar Galactica.  To be able to take off and be effective I must accelerate out the launch tube at a high rate if I plan on killing Cylons at any time in the near future.  What is the net force on me in the launch tube?

The students were quicker to answer this time around but many still hesitated.  The most important concept they should know is force.  Everything else falls out of force.  Hopefully this will stick in there mind.  I can definitely think about physics in terms of Battlestar Galactica for a long time.  I was asked one last question by one of the students:

Can you tell us about any of the specific questions on the test?

I answered again in terms of Battlestar Galactica.

That would be asking me to make an unethical decision. . .like many of decisions that president Laura Roslin had to make while governing the fleet!

Bad activities are bad

So after going over some of the assignments from last week it was noticed that some of the students last week may have decided since the activity was boring they didn’t need to try very hard on the assignment.  I told them in class on Monday that it was unacceptable to not try their best.  I also told them not doing work or working hard affects their grade and more importantly it changes the way people (like their employers) will think about them.

The thing is, I understand their sentiment towards the assignment.  I don’t really do well when given work that I think is a waste of time either.  I understand this “quality” in myself and have to work harder to take busy work seriously at least when I know it is necessary.

The students also are approaching the point in the semester where they aren’t excited about the start of school anymore because now they have real work to do.  I know I get that feeling around 4-5 weeks into every semester.  How do you keep them excited about something when the initial enthusiasm has gone the way of the dodo?

But how do I get my students to do something that I struggle to do myself?  Ideally, we would only assign our students the most interesting and educational assignments as possible.  Assignments that they will eat up and spend extra hours on perfecting.  Realistically this can’t happen every day.  So what do we when we give bad assignments?

When things don’t work

We ran an activity yesterday that taught the students data analysis skills.  How to linearize data, the differences between non-linear data and linear data, and how to plot it all in excel.  It didn’t work very well.

The assignment was designed for one person to complete and it was given to groups of three.  This never works in a SCALE-UP class.  Part of SCALE-UP is getting students to buy into the model.  If we don’t give them assignments that require participation by all people then the students will know and won’t work together.  It was thought that by artificially slowing the assignment down by having discussions between each question on the assignment that would get better engagement but it really just frustrated the students more.  Boredom is anathema to learning.

To be fair to myself, the students are probably getting to the point where the initial excitement of the start of the school year and are settling in to the idea that they actually have to work.  Many of them seemed restless when coming into class.  Many of the students also seemed to already know much of what was contained in the assignment.

The sad thing is that this all leads up to a really exciting assignment.  Their next project will be designing an experiment to test how mass changes a pendulum’s period.  And I believe we could have started with the pendulum assignment.  The students who struggle with the data analysis will ask questions and the TA’s or their peers will help them.  I don’t think they needed to explicitly learn a skill outside of why you would apply that skill.  Maybe next week they will be more engaged.  What do you do when you find your students disengaged from there classwork?

Newton’s 2nd Law – The Momentum Principle

I took John Burk’s advice from one a previous response to my blog post (where he was recommending Andy Rundquist’s approach) and talked about Newton’s 2nd law today in terms of momentum.  Since we haven’t really introduced momentum in the class yet I let that word slip out and then told students that all they really needed to concern themselves with was that the velocity was changing (or not changing).  This worked astonishingly well.  Many of the students seemed to jump on this idea and were able to internalize it quickly to begin answering questions I had about different situations.  This is before we have exposed them to force decomposition, free body diagrams, how to sum all of the forces, etc. etc. etc.

We switched gears and used the Newton’s Laws tutorials from University of Maryland instead of the modelling curriculum worksheets (sorry, no link for the UMD worksheets).  The design of the UMD worksheets are different from the modelling curriculum worksheets.  The worksheet asks the students to state their answers first then ask them to assess whether those answers match up with Newtonian concepts.

This was difficult for the students.  Students are so hung up on getting the right answer because they have been conditioned to do so.  I stress repeatedly in class the only time where I will mark them down for being wrong is on a test or quiz.  I want my students to learn from their mistakes.  I want mistakes to be learning experiences.  I use these mistakes to publicly instruct.

A student showed me her worksheet where she had indicated that to maintain movement a force must be applied.  Instead of having a one on one conversation with her I decided to have this conversation with the class as a whole.  Why?  Because they would all be having that question eventually.  So I had a guided discussion on F=mΔv (this is algebra physics so the notation has to remain with delta’s and not derivatives).

This wasn’t me dictating the answers.  It was me getting enough students in the class (hopefully at least one or two per table) to the idea that there is a net force when there is a change in velocity and no net force when the change in velocity is zero.  Or rather, that a force causes a change in velocity.  Getting at least one or two students per table to understand this is key to SCALE-UP.  If they can understand it hopefully they will feel confident to help the other students understand it.

The conversation between students is key.  I am a person who likes to hear themselves talk.  So it takes an extra amount of work to shut up when a student opens their mouths to explain something.  But it’s worth it.  Watching a student explain what I am saying to another student and that student immediately gets it is one of the key tenets of SCALE-UP (at least my interpretation of it).  This addresses several things I am hoping the students get out of the experience.  Having a student explain something instead of myself helps that student learn to communicate better, it helps them take an idea given to them and re-translate it in their own words and it helps them internalize the understanding better than just hearing me say, “good job you are right.”

What do you think?