Predicting Bridge Strength via Data Analysis (Day 2 of 2)
Lesson 19 of 20
Objective: SWBAT collect data to model the dead and live weight of paper bridges and use the line of best fit to make predictions from the data.
Revisiting Yesterday's Work
The objective of today's lesson is for students to use the data they collected yesterday to create a model and to make predictions based on their results. I begin the day by allowing students 15 minutes to complete their analysis and discuss their scatter plots in their groups. (I have learned to plan for 15 minutes because it is sometimes the case that the students only had time to collect the data on the first day.) As students are completing the patterns in the data, I walk around the room observing different responses. I want students to share with the whole class, and, I want to sequence the order of sharing.
After allowing students about 15 minutes to work together, I will call on students to share out. I have made a list of students to call on as I was observing their discussions I want to discuss the importance of precision (MP6), and I usually have a few students with well formed ideas for why this is important to the project. I also want students to practice using vocabulary such as regression, interpolate, extrapolate, and measurement error.
This activity is a simple simulation of the type of process engineers complete when they design and test a design for a bridge. As a closing activity I want to help my students to make this connection to a real world situation. Along with this real world connection, we will also discuss students' results. Here are some topics that usually occur:
- The slope of the line represents the additional live weight (# of pennies) the bridge is able to hold when a new layer is added.
- The y-intercept should represent the weight of the bridge without live weight. It is always interesting to see that many students get a y-intercept close to 0.
- The students had to write the equation for the line of best fit and predict how many pennies the bridge could hold if the layers of 6 and 7 were added.
Teacher's Note: In a future activity I will have my students compare their results by hand to the equation for the line of best fit from the calculator. So, we have not used a calculator for this project. However, the graphing calculator could have been used with this lesson.