On the first day of our Solar Vehicle Engineering Design Project (SVED) my objective was that when given a client context, students are able to ask questions in order to define a complex problem and identify criteria for success by reading a client context and negotiating priorities with a group of 2-3 other students.
The assessments I would use for the days learning objective were included in the Engineering Report, which was handed to every student. The first page of the report provided the structure for the assessment of this learning objective.
Before starting the project, I had closed our last class meeting with a question: can the sun provide us with all the energy we need? I had told them about how when you think about it all of our sources of energy actually originate from the sun (e.g. fossil fuels come from animals that ate plants or ate animals that ate plant which got their energy from photosynthesis which is triggered by the sun). I had spent some time the days leading up to this launch researching solar energy, solar cell technology, and anything related to the topic, because while I, myself, do not have an expert understanding of the topic, do consider it an important issue to bring into the classroom. I talked to students about the cost of solar energy, how it costs four times as much to provide energy from solar cells than from fossil fuels. Students had many questions: Why is it so expensive? Will solar energy ever be cheaper? I showed students the video TED-ed: How do Solar Panels Work? And that’s when the bell rang. I encouraged them to continue to think about and research this topic between now and the next class meeting (two days later).
The next class meeting, I launched the project with a story: So I was approached by three local companies who all happen to need some sort of vehicle (I had the fake logos that I ripped off of the web last minute displayed on the board behind me as I elaborated on the fiction). They all had heard about the amazing engineering teams that are hosted in this classroom and wanted to propose that we come up with the best possible solution to their problems.
Then, I basically go into each of our three clients, summarizing what they would eventually read on the client cards:
- Progressive Builders Construction Company
- Cougar Car Company
- L.S.T. Inc.
I had spent weeks mulling over and refining the words that would go onto the client cards--they are crucial to the success of the project. In my story-launch my aim was to engage them, or hook them into the motivation for the project before handing them any worksheets or anything that resembled school work. But later on in the project, the client cards serve the super important purpose of providing the context for their problem. The cards had to have enough detail to imply value of some criteria over others, but not too much that it gave the answer away.
After I finished my initial briefing of the three clients to the class, they were ready to choose. I told them I would pass out a client card to each student. Each card had the context for one of the three companies that were interested in working with us. They had the choice of keeping the client card they were handed or trading with someone else for another client. I had two rationales for doing this. 1. I had control over the number of students that were assigned to each client, meaning I’d have a balanced number of teams for PBCC, CCC and LST. 2. It gave the students the opportunity to choose who they wanted to work with. After they decided on the client, then they could start to form teams of 3-4 who also had chosen that client. Of course, right away students were negotiating among themselves which client to go with and concurrently whether they wanted to work with certain people or not.
Students were tasked with writing out a problem statement once they had chosen their client, team, and read the Design Brief. The Design Brief provided students with all the information they need to know about their client in order to design the best solution. This resource was supported by the work done by the Georgia Youth Science and Technology Centers, although I picked it up from an NSTA 2016 session called “Argumentation by Design: Integrating Evidence-Based Arguments with STEM Design Tasks“ presented by Amy Peacock (Clarke County School District: Athens, GA), Jeremy Peacock (Northeast Georgia RESA: Winterville, GA), Paul Blais (Burney-Harris-Lyons Middle School: Athens, GA). They share and post all their resources to the public for free on http://bit.ly/ArgueByDesign.
Most students chose to work with the group of others that they consistently worked with, while I was happy to see some others branch out. They had about 20 minutes to form their problem statement. In previous engineering design projects, they had also used a sentence frame to form their problem statement. While most groups took their time to form a more specific problem statement to guide their design, a few needed some extra probing my me to get them to think about the specific reason, or main criteria for their design. My job was to help guide them in this aspect of the engineering design process.
We as engineering seek to design a solar powered car in order to utilize sustainable source of energy for Cougar Car Company.
vs.
(not pictured) We as EHS engineers seek to design a solar-powered vehicle in order to provide a fast racecar for the Cougar Car Company.
The next part of the lesson was by far my FAVORITE. A decision matrix was introduced to me during that NSTA session previously mentioned. I was hooked to the idea because it allowed for a way to prioritize criteria in a way that is more objective and methodical than any other way I’ve seen students use. I also liked that the decision matrix replicates an authentic engineering practice, which I understand to be true based on anecdotal evidence (someone at the workshop said so). At this point, I told the class they’d be working with the criteria: cost, acceleration, load capacity, and durability. Yes--I could have had them determine four criteria themselves, but in an effort to provide more scaffolding and control over the materials and anticipate student answers I chose to assign them. The decision matrix uses votes from each team member to assign a value to each criterion. One team member acting as both facilitator and participant, goes around the group and asks to compare relative value of criteria. For example, to fill in the first non-shaded box, the facilitator asks “How many think that acceleration is more important than cost?” then writes the number of votes into that box. And for the next box in the row, facilitator asks “How many think that acceleration is more important than durability?” and writes in the number of yes-votes. The end product is a list of values assigned to each criterion, thus providing students with a quantitative way to assess and consider how important a certain feature is to their design.
This part was my favorite because of all the awesome talk I heard. Seriously, I wish I could’ve had an audio recording of the class during this time. It especially helped that students were mostly working with classmates that they felt comfortable with. Even with using the decision matrix, it wasn’t important at all that there was a consensus. They were allowed to disagree on relative value. However, I heard and saw students analyzing and interpreting the text (Design Brief) to support their assertions that one criterion was more valuable than another for their particular client.
For Cougar Car Company:
“They want it to be just as fast as their regular gas cars… no matter the cost… so we can spend as much money as we want”
“I mean, load capacity matters but they really only need to fit one person in the car--the driver. They don’t need any more than that so it’s not as important”
For L.S.T. Inc.
“It is probably better that is goes fast because then the tourists can see more places and they’ll pay more.”
“But we need to build it cheap so that they can make money off of it, and if they make more money off of it then it's okay if it’s not that durable ‘cause they can afford to replace it”
For Progressive Builders Construction Company”
“It doesn’t seem like they can afford to spend that much, but it would be better if it lasts longer.”
“It says they want to use it to carry as much dirt as possible, but if it’s fast then they can go back and forth more”
Once they had completed prioritizing their criteria, they were prompted to move into Design Exploration. From previous engineering tasks, most remembered that they are expected to work by themselves for at least the first few minutes, and then compare ideas and provide feedback. Many groups used this time to pick up their materials to get a sense of what was available. This was where most groups left off, although I used this time to monitor progress among groups, eventually letting a couple groups know that they were behind where they needed to be at this point in the project in order to stay on track to finish.
Each team was given a plastic box (99 cent store) with a 2 V solar cell and DC solar motor, wooden base board, set of four gears, four wheels, two axles, a straw, and samples of the three building materials they have to work with (foam, cardboard and card stock). They were told they may store it in the classroom or take the box with them. The solar car parts are from Kelvin .
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