Engineering Earthquake Structures: Day 2
Lesson 4 of 7
Objective: Students will be able to analyze multiple design choices to determine the most effective design for a prototype.
Over the course of 4 – 5 days, students design earthquake resistant structures based on their research of seismic design principles. Along the way, students utilize scientific text strategies, engage in scientific discourse based on evidence, experience the engineering design process and are introduced to the advantages of digital vs. analog signals. Components of this lesson connect to the following NGSS and Common Core Standards:
MS-ETS1-1 Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions.
MS-ETS1-2. Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.
MS-ETS1-3. Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success.
MS-ETS1-4. Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process.
MS-PS-4-2 Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.
MS-PS-4-3 Integrate qualitative and technical information to support the claim that digitized signals are a more reliable way to encode and transmit information than analog signals.
On day one, students analyze text so that they can obtain and evaluate information (SP8) and engage in evidence based discussions (SP7).
Day two, students use a design matrix to determine which design solutions meet the criteria (ETS1-2) and begin testing their designs on the shake table. In determining the criteria in their design matrix, students use research that provides insight into the patterns (Cross Cutting Concept Patterns) in the causes of structural damage caused by earthquakes. In addition, students connect these causes to the effects of implementing seismic design principles to structural design.
On day 3, students begin to shake their initial prototypes and collect qualitative and quantitative data to create new design solutions. In addition, they work on generating questions and engage in scientific discourse as they explore connections to wave properties as the listen to the "song" or "sound a comet makes" that was collected by the Rosetta probe that landed on Comet 67P/Churyumov-Gerasimenko!
On day four, as students test their earthquake resistant structures they improve their designs based on the results (ETS.1). Moreover, students compare their results with other groups and designs to incorporate all successful components into a “super design” (ETS1-3). In addition, students are introduced to the difference between an analog and digital signal.
Day five of this lesson asks students to look at real world constraints and impacts. After developing their classroom prototype, students consider real world implications to society and the environment. They recognize that technologies have limitations and that while prototypes meet our societal needs and wants, they also have short and long term consequences. During this lesson, students further their understanding of analog and digital signals as the teacher takes the students through a visual model/analogy with a children's swimming pool!
Ask students, “What are you going to learn today?”. Students should respond by stating something connected to the NGSS Essential Question (I keep this posted on my front board.). Thus, students might say, “We need to answer the question, what are the characteristic properties of waves and how can they be used in the world?”
Explain that our focus over the next days is how waves can be used. Remind the students that scientists and engineers use data they collect from seismic waves to develop solutions in building designs.
Note: As this lesson is one of the last in the Waves unit, I also have students begin to prepare for their assessment by reflecting on their growth as related to the essential question. The reflection explains one way that I have students complete this.
Say, “When engineers design and work in a team, they strategically choose the design they build first. It’s not just the person that is the “loudest” whose design is chosen. They base their decisions on criteria identified by the team as being important for success. Today, after your group has finished their research and drawn sketches, you will be completing a Design Matrix to choose the prototype you will be constructing first.”
Ask students to turn to the Design Matrix in their student document.
Say, “Each row represents a student in your group’s design idea. The columns represent the design principles that your group determines are the most important to consider. Your group will discuss these and write them in. Each member of the group will then describe their design to the group and explain why they think that it will work. Then, each member of the group will rank the design on a scale of 1 – 4 (4 being the best) for each design principle. Add each column up and place the total in the last column. After each member’s design has been ranked, choose the design (based on data) that will be the first prototype you build.”
Say, “Now, if Student A’s design has the highest total, but Student B’s design had one design principle that could be added, by all means go ahead!”
“After ranking your designs in the matrix, you will then approach your client (me) about building your prototype. As per your client’s request, you must come ready to show the following:
- A sketch of your prototype.
- A verbal explanation of your design choices – You must explain the why you feel your design will be successful. The client would like you to cite research and seismic design principles in your explanations to prove it is founded in science and engineering.
- Proof that you considered multiple designs and evaluated them based on criteria (Design Matrix).
If sufficient evidence is provided, I will approve your prototype construction and you can begin building. Remember, as you test you need to take quantitative and qualitative data in the provided data table. Future approval of new prototypes will be dependent on it!”
As students come to you ready to build, make sure that they are citing evidence directly from the text and that their designs reflect seismic design principles. In addition, look at each member of the groups design matrix. It is essential that each group goes through the process of choosing a design based on criteria. In my experience, I find that students are so excited to build, they start cutting corners here. Only approve prototype building based on evidence!
Students first complete their research and complete a sketch of their prototype:
Students then explain how they decided on a prototype design using a Design Matrix:
Have students continue to work on the Seismic Design Principles Challenge. Remind them that prior to building, that they must come to you, their client, with their plan and be able to cite evidence of why their design meets seismic design principles that will allow their structure to resist the shake. In addition, remind them that they must collect both qualitative and quantitative data for each structure in the data tale on their lab sheet. In order for them to build their next prototype, they must show data and evidence of the improvements that they will be making.
On Day 2, students typically do not complete their first design. Shaking begins on Day 3!
Have groups meet and assess where they are in their process, and make a plan for the following day. Students write this on a slip of paper to give to you as an "Exit Ticket". Reviewing / sorting the slips prior to the next day gives you a critical starting point with some students.