Yesterday I was asked to cover a class for one of my colleagues, so I planned another round of digital fabrication activities for his students. I had done the same thing last week with another colleague's class, using the materials I developed last year. The first attempt last week did not go nearly as well as I remembered the activities going last year, so I was motivated to rethink how I was presenting the content, as well as the activity I was having them do. The "old" activity was challenge that involved designing a container for tootsie rolls that would maximize the surface area:volume ratio. The concept was good, and the students approached it with enthusiasm. However, it turns out that their math abilities were a pretty major roadblock to getting anything substantive out of the activity. After the box was built and they stuffed it with tootsie rolls, the learning was basically over. This issue has roots in several factors that are true of most preservice teachers.

  1. Preservice teachers' pedagogical knowledge has more to do with their worldview than their aptitude or attitude. Since most of them were taught from a traditional approach, the chasm between problem-based design activities and the lecture-test-essay model they are used to is a quantum leap. The problem is not that they are resistant to new pedagogical approaches; they simply have very little, if anything, to which to anchor them.
  2. Before preservice teachers can understand something as a teacher, they need to take a step back and experience it as a student. Activities, therefore, need to be authentic and replicate, as much as possible, the way it might be done in a classroom.
  3. Based on the previous two observations, if the instructor wants preservice teachers to abstract pedagogical principles from an authentic activity, he or she is going to have to lead them there. You can't expect inexperienced teachers coming from a traditional paradigm to naturally make connections between the activity they just did and broader educational ideas. It's like giving someone from a remote tribe in the Amazon rainforest a debit card and expecting him to naturally gravitate to an ATM and get some cash. The notion that there is "money" in a "bank" that can be "accessed" remotely just does not mesh with the way he thinks the world works.
  4. Finally, authentic activities must be accessible. That is, they can not be too hard nor too easy. If the activity is too easy, the preservice teachers think it is fluff and busy work; if it's too hard, they can't envision themselves teaching that way. Either extreme will likely reinforce the worldview you are trying to change.

To improve on the previous activity, with these observations in mind, I designed the following challenge:

  1. I started by describing the mentality of many students today, which is that every task they are given in school has a right answer, and their goal as students is to get the right answer the first time. Many teachers reinforce this mentality by how they conduct their classes. At present, the world works much differently than classrooms do. In the world, we encounter problems to which we must develop solutions. These problems are typically ...
    • Ill-defined: the cause of the problem may not be readily apparent
    • Ill-structured: because we don't know the cause, we don't know where to start exploring solutions
    • Complex: there are many factors involved, each of which influences the other, and we don't know how changing one factor influences the other factors
  2. I then tell them the story of William, a 14-year old boy from Malawi who had to drop out of school because is family was literally starving to death. They could no longer pay for his education, so he used the library to try to educate himself. From reading physics and "green" energy books, he got the idea of improving his family's way of life by building a windmill and generating electricity for his home. Using the images and diagrams from a book on wind energy (he was not able to read English very well at the time), he built his own windmill from old car, tractor and bicycle parts and provided electricity for his home. Soon, people from all over came to his house to charge their cell phones. Not long after this, he built another windmill to pump water to irrigate his family's crops.
  3. I transition to the next point by telling the students that William solved his problem by using the resources available to him to create a solution to his problem. This took several attempts, and you can see how he improved his design from the first windmill to the second. In the same way, teachers need to provide opportunities for their students to solve problems using their available resources. Since there is no single right answer, students must be evaluated using different criteria.
  4. I then talked about a new set of resources that students have access to. We talk for a minute about how everything they use now was first designed in a virtual 3D environment before it became a physical object we can use. I took a minute to show them ModelMaker, a simple tool for creating 3D shapes from 2D cut-outs.
  5. I then explained the challenge, which was create a windmill that was able to lift a bucket of tootsie rolls. They would construct their windmill using card stock, a pencil and masking tape, and they would design their bucket using ModelMaker. The group able to lift the most tootsie rolls would win the  challenge, the prize for which was getting to eat as many tootsie rolls as they wanted. :-)

Here are some pictures of the activity ...

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In summary, this activity was a vast improvement over the previous activity. The preservice teachers were able to see for themselves how their design choices affected the way their windmill functioned. Some groups created a "cute" windmill that would not spin, while others created an aesthetically bland windmill that performed wonderfully. Some groups put more focus on the size of their container than they did on the design of their windmill, and one group created a wonderful windmill but their bucket too small. Had the bucket been bigger, they were convinced it could have carried the most tootsie rolls. For some of them, the fact that they created a machine that actually worked was very rewarding in itself. I will do some follow up with my own students to document their reactions, but my impression was that this was effective and worthwhile. And in the spirit of engineering and the design process, there was room for improvement.