Southwest Michigan Modeling Workshop Day 6

One of the great questions that the participants have is, what do you do with homework?  In a traditional setting it probably looks a lot like a math class.  The teacher assigns homework the kids go home and "do it" then the teacher spends 20 minutes standing at the board "going over" (which probably means just doing the problems for the kids) the homework.  

I don't know any teacher who actually likes this method.  Most are disenfranchised but don't know any better way!  So is there a better way?  Totally.

Both Laura and I do something similar.  We assign homework and the next day the students get grouped and assigned one or two of the problems to put on a white board.  They get together to do this while the teacher walks around asking questions and making observations.  

Then we "circle up" and each group presents their work while the teacher and the students ask questions.  

We modeled this yesterday with Laura as the facilitator and the participants in student mode.  This went very well - occasionally they fell out of student mode - but I feel like everyone got a good sense of how to do this.

We them completed the ball and buggy collision practicum - with significantly more success than the T-Bone Challenge from the other day.  I am still struck by how amazing these practicums are.  We have a great group of participants but their level of physics content and practical knowledge varies.  So these practicums instigate some very real dialogue between them.  There were 4 groups and 4 different methods for doing the activity.  I can't say enough about how important these are in the class and for the workshop.

After that we started in on unit 4 - the Balanced Forces Particle Model.

Unlike the previous units, where the unit hinged on a paradigm lab, the BFPM starts with a discussion where the teacher facilitates the model development through dialogue, agreement and consensus.  It is a different strategy.

The problem is that it looks so much like a traditional setting where the teacher is doing a lot of the talking and probably in front of the class.  Don't be fooled!  The teacher is asking about 100 questions trying to draw out the student's ideas about forces.

The goal is to come to a class consensus about what exactly a force is, how we should represent them and are there conditions for balancing our forces.  This happens through a long rather protracted dialogue between the teacher and the class.

One of the conclusions that the class invariably comes to is that if the velocity of your object is zero then the forces should be balanced.  Now - just because that isn't necessarily true doesn't mean we should dismiss it entirely.  It is a stepping stone to get to a better concept.  

So I wrote it on the board and when presented with more information - a hover puck moving at a constant speed (non zero velocity but still constant forces) we had some cognitive conflict and had to revise our model.

We then put some problems from unit 4 worksheet 1 on some white boards.  Worksheet 1 is a very important worksheet because it really puts the participants (and students) in a position to do a bunch of force diagrams.  The modeling method doesn't always promote repetition as a road to mastery.  However, this deployment is a great opportunity for them to really get a handle on force diagrams.  

We then presented these white boards in a board meeting.  At the end of the 6th day people were getting pretty tired.  So we suspended the board meeting to do something fun.

We used some spring scaled to find out if there was a relationship between mass and weight.  To do this I put tape of the "grams" side of the spring scales so that the only side they can read is the "Newtons".  The research question is, "What, if any, relationship exists between mass and weight?"  This was pretty easy for them and pretty quickly they were finished with the white boards and we presented them.   

The problem was that some groups worked in grams while others in kilograms.  I was purposefully vague so that the boards would be different and we could have a discussion about what to use and when to use it.

They reported the slopes as 10 N/kg and had good "for every" statements and then the day ended.