Designing a Solar Car Part 3
Lesson 3 of 7
Objective: SWBAT use scientific knowledge to create several solar car designs.
This section is all about finding the best design solution to test. In Part 2, students have started their preliminary designs and have conducted research. In Part 3 my strategies change from getting information to using information to develop design solutions.
The steps of the design process are being used as students gather data, draw ideas, and collaborate to determine the best design solution. Refer to my lessons, I Have to Teach Engineering? and Dream Invention for more about the process of engineering design.
Students return to the research from Designing a Solar Car Part 2. In Part 2 I asked them to consider the question, "What is the most important information necessary for designing a solar car?" I explain that they need to re-read the information their partner answered in an effort to determine the most important information necessary for designing a solar car. This is not a partner activity because the research partners may not be their design partners. Students go to their own computers and read all the information and look over the images. In their notebooks, they make a bullet point summary. They can draw or write phrases, summarizing what they think is the most important information for the design of a solar car. They will use this information later when they make design partners.
In the movie below, the students are explaining what they think is most important and why.
Students now have four distinctly different ideas. It is time to collaborate. One of my favorite sharing strategies is called Give One-Get One. It is useful on many levels. If I say to the students, "Go share," they will share ideas and sit down. There will be little back and forth of conversation describing the attributes of the ideas.
Instead I say, "I want you to look over your designs and decide which you like best and why. You are going give an idea and get an idea." Students need to make a plan for a discussion. They think about how to describe the idea. Then, with a partner they are providing rationale for an idea. By offering the students the opportunity to describe an idea with a partner, I am building the bridge to the writing component of lesson, when students defend an idea in writing.
The strategy starts when I ask students to find a partner. They move to quiet place in the room to give and get an idea. When they are done I ask them to pick another partner. We do a couple of rounds until I ask, “Do you need more ideas?” If they say yes, I allow a few more rounds, listening carefully to their ideas.
My job is to go listen to the sharing of ideas looking for misconceptions. As I listen to students I may find a typical misconception that I want to address to the entire class. In my Reflection, Assessing Misconceptions, I address critical information about a strategy for helping assess misconceptions called It Is/It Isn't. Using this strategy I can be sure the students have made the connection between the design and the science necessary for a successful design.
As students go back to their tables I ask students to reflect with the question, “Did this help your learning?” The students almost always emphatically say, “YES!”
Finally I ask them to choose their best idea and redraw it on a large piece of graph paper. They ask, "Can I change it?" I emphatically say, "YES!". Some students will redraw an existing idea but for the most part they make subtle changes based upon the collaboration.
Determining The Criteria
Students have brainstormed and considered four unique designs for their models, choosing one as their best design. They have conducted research and they understand how solar panels work. Put in Solar lesson here. Now it is time to determine the criteria.
I ask, “What does "criteria for success" mean?” Students respond that it means what you need to be successful. I ask students to go back to their research to determine what they think is the most important criteria for success. I use small group discussion strategy. Students work in small groups to develop criteria. When they are done, I project the criteria on the board and ask them to consider the most important criteria. At this point I let the students lead the discussion. They determine the four or five most important criteria.
My next strategy is called “Have you thought about...?” I want the students to evaluate their design against the criteria. To help them, I ask students to find a partner. The partners must go to a quiet place in the room to evaluate ideas. They trade designs and then say, “Have you thought about…?” I listen to the responses and answer questions. Students choose a different partner and repeat. I’ll go several rounds before I ask, “Does anyone need to go another round?” I’ll go a few more rounds, listening to the responses. To assess the activity I ask, “Did this help?” I usually get an enthusiastic “YES!” I offer time to change drawings so the final designs follow the criteria.
Evaluating Design Ideas
The next evaluation strategy I use is called Using a Decision Matrix. A decision matrix quantifies design ideas with a rating scale. I hand the students a worksheet called Decision Matrix. They write each tablemates name in the rows and each of the criteria as column headings. They rate ideas based upon a 1-5 number system, 5 being the highest. Students trade notebooks and rate one another’s designs. They then add the ratings to determine which idea is the best.
This strategy allows groups of students to look over the designs with an evaluative eye. They have shared design ideas, offered suggestions for improvement, and now the quantitative evaluation helps them understand how the criteria determines the best idea.
Students have now had a opportunity to look at different design ideas and I want them to work with partners. I use a strategy called Blind Man's Bluff. Students place their designs on their forehead to show one another the designs. I use it to create authentic partnerships. I don't want students to partner with their best friends. They need to be with someone who has a similar design idea. In the movie below I explain how the students will pick authentic partners using this strategy.