# Raising the Bar: Modeling Part Two

For the opening round, here's Part One.

Now that we set the stage for modeling, I set my students on a lengthy task. A big flaw in my teaching is that for whatever reason, no matter how hard I try, self-guided tasks have a tendency to blow up in my face. A lot of my experiments last year could've been a lot better with a bit more structure and I thought we'd finally get it this time. I took time to give a tutorial on the final product AND I gave them these instructions the day before:

And yet, for whatever mystical reason, I had to do a lot of hand holding during the construction phase.

### Movie Making

First phase of the task went pretty well. After a little prodding all the groups got set up and they knew what they had to document. Questions arose about how to demonstrate a positive parabola with a tennis ball. Lots resorted to bouncing (which begs the question, is a quadratic REALLY the best choice for that?), a small handful decided that the initial portion of an underhand toss would be a better choice.

I checked with each group to see that they were collecting the right things. I had to point out which measurements to get sometimes. All of this was in the instructions and yet all they heard was "make a couple videos." Ugh. A few groups who forgot to measure decided to gamble and scale stuff off the video. Later in the process I offered the suggestion of having a person stand in the middle to provide better reference when trying to determine the maximum height of the ball. All in all, everyone was able to gather data that made sense.

### Analysis and Assembly

This was all over the place. In order to generate enough work for 4 people, there were enough iPads such that the minimum and maximum analysis photos could be done simultaneously. This solved a problem I had last year where 6 kids were trying to stare at a single screen and most gave up. A secondary task was to extend our penny modeling exercise to coins of different sizes for kids not involved in the video dissection. They were given circles of random size to collect data and set up the graphs. This part fell flat, but a bit of that was my fault.

For two classes, I didn't structure their analysis process. I kind of said: make sure you've got these points, we've already talked about how to make quadratic equations from them, go and make magic. Maybe 40% needed some serious hand holding. Ignore the fact that we TOTALLY did classwork that supported the math here with NO PROBLEM two days before but hey, go ahead and stare into space. Thus, for my other two classes, as soon as we came inside I was like WE ARE FIGURING THE MATH PART OUT RIGHT NOW. Less hand holding required. These two classes were able to immediately jump to the Desmos graphing overlay. The two struggling classes limped to the overlay generation a bit slower, but we got there. And like I said in my post about the tutorial, I had to do very little intervention here. A few weren't lining the scale up properly to make sense with the picture, but no one was giving me blank stares about how to change the opacity of a layer.

Though more difficult than it should have been, everyone was able to arrive with a final product. Many produced overhand models that matched pretty well. A lot were off, but that's totally the point of the exercise.

### Room to Grow

To recap the problems from last year:

• the math component was unreasonably difficult for the students
• the meaning of the activity was obfuscated
• the wasn't enough technology to go around

I think all of the major problems were successfully addressed. I still seem to suck at self-guided activities. Intervening as I did with two of the classes created fewer headaches, so a mental note for the future there.  I make it sound like there were major struggles with the math, but really maybe 8 students out of a 100 generated the rage. I had to do some double checking here and there, but almost everyone knew how to at least start the process. Having more iPads and a color printer increased the usefulness of the output significantly.

My neat extension idea on the coins was a big fail. I didn't ask the right questions. A lot of them produced the equations but gave me "what's the point of this part exactly?" looks. To fix it I needed a specific objective: "how many quarters in a 12" circle?" for example.

Overall, the whole process was a B+/ A-. Needs a few little fixes to make it A+.  I cashed in a lot of class time only to have everyone to conclude that modeling was a crapshoot, but the act of doing was far better than what the textbook has to offer.

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