This project was designed as a Problem Based Learning module. The original letter was written by one of our teachers to the Chemistry 2 class asking them to develop the experimental design and collect the data. This class performed our feasibility study to ensure that the CO2 levels were measurable and showed a noticeable pattern over time. It was decided that the PBL would work best as a cross-curricular assignment for several reasons. The module is relatively large and sharing the learning among several classes minimizes the class time involved while maximizing the benefit to a wider range of students. The parts of the project will be handed back and forth between the classes. This will cause the students to take their work more seriously because their peers will be using their results. The students will make the connection between the mathematical representation and the experimental model because both math and science students will be involved in the analysis.
Problem Based Learning begins when the class "meets the problem." Science Writing will begin this step using the Know/Need To Know boards. As they develop the Need To Know section, they will be encouraged to communicate with the Chemistry 2 class to request background information on CO2. Chemistry 2 will be the "technical experts" in this project. As the Science Writing students develop their understanding of the problem, they will add to the Know and Think We Know sections of the Know/Need To Know boards and they will begin to develop the model of the system using STELLA modeling software. This thought process should help them to develop a clear problem statement followed by a well-designed hypothesis. We will expect our students to "toggle" back and forth among their Know/Need To Know boards, the Stella model development, and their experimental design diagram. We use the experimental design diagram recommended in Students and Research by Cothran, Geise, and Rezba to help the students develop their problem, hypothesis and procedure. The Science Writing students will write a procedure and hand their work off to the Chemistry 2 students.
The Integrated Math 1 students will be asked to measure the test classroom dimensions. This will be completed using a Calculator Based Ranger. Once measurements are made, they will calculate the room volume and convert the calculated value to liters. This information will be shared with the Science Writing and Chemistry 2 students.
The Chemistry 2 students will use the procedure written by the Science Writing students along with the developmental STELLA model to collect the data and to analyze the chemistry. They will also be responsible for researching and writing a report about the carbon dioxide chemical background information. As data is collected, they will make necessary modifications to the experimental design diagram to collect the most appropriate data. They will share the collected data with math classes for analysis.
The Integrated Math 2 students will analyze the data sets looking at one class period's carbon dioxide versus time graph. Using the data points on a TI-83+ calculator, they will run several types of regressions to determine the line of best fit. They will form conjectures about what is happening in the classroom and send their mathematical analysis to the Chemistry 2 and Pre-Calculus students.
The Pre-Calculus students will analyze all data sets using TI-92+ calculators determining the whether it is a continuous or discontinuous function. They also will look at the STELLA model and determine if their mathematical analysis correlates to the model. They will send a written analysis to the Science Writing students.
Since this is a PBL and our students will be required to create their own STELLA models, we chose not to post our sample model on this site. Please send a request for a sample STELLA model on school stationary and include your email address. Requests should be sent to Tyner Academy, attn: Joey Hatcher, 6836 Tyner Road, Chattanooga, TN 37421
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