Summer Research Program for Science Teachers
August 2004
Emily Beth Noto
East Side Middle School
Manhattan
Hurricane Unit
Water Cycle Variables
Lesson Rationale: The purpose of this lesson is to explore the factors that affect the rate of the water cycle. In previous lessons students explored the steps of the water cycle, examined the unequal heating of the earth’s surface and discussed the role of the water cycle in hurricanes. Students will be able to design and carry out experiments to test how different variables effect the rate of the different steps of the water cycle. In future lessons students will evaluate their data and results. Each group will replicate another groups experiment. Then the class will use its experience to formulate theories about the rate of the water cycle. Students will make connections to how their conclusions influence the formation of hurricanes. This lesson will take two class periods.
National Science Education Standards: 1. Encourage and model the skills of scientific inquiry, as well as the curiosity, openness to new ideas and data, and skepticism that characterizes science.
2. Students should develop understanding and abilities aligned with the following concepts and processes: evidence, models and explanation.
Materials: Water
Plastic dropper
Petri dishes
Index cards
Stopwatch
Lamp
Beakers
Plastic wrap
Ice
Hot plate
Aim: SWBAT design experiments to test the effects of different variables on the rate of water cycle.
Do Now: List possible variables that could affect the rate of the water cycle.
Agenda: 1. Brainstorm a list of variables (first class)
2. Students design experiments in groups (first class)
3. Students present experiment plan (first class)
3. Students do their experiment (second class)
Anticipatory Set:
Discuss the variables that could affect the rate of the water cycle. Anticipated student responses: amount of heat, amount of water, wind. Possible questions to facilitate discussion: What do you know about hurricane formation that could indicate what variables will affect the water cycle? What are the characteristics of the environment in which hurricanes form?
Lesson Body:
m Teacher says, “Today we are going to design experiments to test the effects of different variables on the rate of the water cycle. I will assign each group a variable and as a group you will design an experiment.”
m Teacher assigns each group a variable and describes the materials that will be available to the students. Most student responses for the anticipatory set will be some variation of heat or wind, the teacher may choose to focus on those variables.
m In groups students design an experiment to test their variable. Each student is responsible for one aspect of the design: hypothesis, materials, independent and dependent variable, controlled variable, and procedure (two students may work on the procedure). Teacher circulates to facilitate group work. Possible questions: How will you know your data is only affected by one variable? What do you predict will happen? Why? What scientific theory have you learned that is applicable to this experiment? Is your procedure clear and detailed? Could it be understood and followed precisely by someone outside your group?
m Students present their design to the class. Students offer feedback and suggestions to each group. Possible questions to facilitate discussion: Where are there possibilities or error? How can you eliminate or lessen experimental error? How will you keep track of your data?
m Students revise experiment. Possible questions: What feedback did you get from the class that you hadn’t considered? How will that change your design?
m Students do experiment. Teacher circulates to monitor student progress. Teacher helps students reflect on their work while they are doing the experiment to make sure they are following their plan precisely.
Closure: Students reflect on their work. Each student reports to their group one thing they felt was successful about their work today and one thing the group can improve or do differently next class.
Homework: Students write a reflection on their experiment: What do you think went well? What obstacles did you encounter that you didn’t anticipate? Do you feel that your data is reliable? Why or why not? Do your results make sense given your background knowledge? If you were to repeat the experiment what would you do differently?