Do Leaves Change Color All At Once? Part II
Lesson 12 of 14
Objective: Students will use the data they have collected to answer the question: Do leaves change color all at once?
I Can Analyze Data
Students have collected data in their journals about the leaves changing color on their tree. They have photographs, drawings and leaves pressed in wax paper to help document the changes they noticed over the past 2 weeks. Today they will take the time to analyze the data and determine an answer to the question we posed in part 1 of this lesson, "Do the leaves on trees change color slowly or all at once?"
I begin with the I Can statement. I post it for students to read with me. It says, "I can answer the question, 'Do leaves on trees change color slowly or all at once?' by looking at my journal and talking to my classmates."
I tell students, "Today you will begin by looking through your own journals at the pictures and leaves you collected and what you recorded each day for whether a few, some, many or all of the leaves had changed colors. You will take the new journal page and write your own answer to the question and tell why you think so. You do not need to have the same answer as the person next to you so take the time to look at your own work and come up with your own answer. "
It is important to let second graders know that they do not need to have the same answer as everyone else. I want to encourage the students to think like scientists so I say, "Remember that scientists take their ideas, collect data and come to their own conclusion. They do not check to see what other scientists do until after they are done with their own work, so we won't share yet."
Sharing with Partners
To begin this part of the lesson I ring the bell to get everyone's attention. I say, "I want you now to talk to your classmates about how they answered the question. You can each tell what you decided, and also read your partners the because part of your journal. This part is the most important because it shows how you decided on your answer. It is ok to have different answers. That is often true in science but scientists need to be able to tell each other why. Do you think you can share your because statements? Thumbs up if you can do that?"
This lesson is helping students develop skills in defending their own conclusions. I hope that as they do this they will improve their ability to discuss issues of science which is something that runs through all levels of scientific thinking.
I break students into groups of 3 to allow for each child to have a chance to share and be heard. I try to put a more competent speaker/explainer with one who may have more difficulty to encourage students to learn from one another. Also the more competent explainer may be able to ask questions that will draw the less competent speaker out. I review with students the rules we have created for working in small groups (listen, be respectful, make sure everyone has a turn, take turns).
I give students about 10 minutes to share out. I circulate around the room to encourage students to share the "because" statement. If I see that students are having difficulty engaging in a meaningful conversation, I may ring the bell and suggest several questions they could ask of each other, such as, "how many days did you only see a few leaves change?" "did you record that it went from a few to many in just 2 days?" "Can you show me your pictures from when only a few leaves were changed to when most of the leaves changed?" These questions will provide students with some ideas about how to ask each other questions and to find out more information from one another. Students may not be ready to think of questions on their own, but by providing some, I am providing samples that students may build from as they learn to engage in meaningful discussions about science.
Class Graph and Closing
I ring the bell and ask students to take their journals and return to their own seats. I say, "I have heard students say that the leaves changed slowly and some who said quickly. I have also heard some good reasons for this. Could we have 2 or 3 people share their answer and reason with the large group?" I call on several volunteers to do this.
I ask for a show of hands for whether students answered that it changed color quickly, slowly or all at once. We talk about why we might have different answers here. (different kinds of trees, different amounts of sunlight, different opinions.)
I choose here to finish this data collection with a graph. Scientists often use graphs and tables to show their results. I want students to feel that there is closure on all the data collecting they did and a graph will bring the experiment to a close. I can connect math and science here and reinforce for students how math and science support one another. It is important for students to see a science experiment comes to a conclusion and so I have chosen to create a graph to support that feeling of conclusion for the data collecting.
"To finish this experiment, we are going to create a class graph of when most of our leaves changed color. I would like you to go back to your journal and on the first day that we collected data write a 1. On the second day (give date) would you write a 2. On the third day (date) write a 3. On the fourth day (date) write a 4 and on the fifth day (date) write a 5." I circulate around to make sure that students are recording the numbers correctly.
"Before we make our graph I am going to give you a small piece of paper. I would like you to draw one of the leaves that you pressed in wax paper. You should use crayon for this." I give students a few minutes to draw and color their leaves. I circulate around and place a piece of tape on each student's desk as they are drawing.
"Now would you find the place where you first recorded that most of your leaves had changed color. Look at the number you just wrote at the top. That is the number we will use in our graph. I have given you a piece of tape to use to tape your picture to the graph. When I call the number of the day, 1,2,3,4,5, or not at all if you never said most, you will come up and tape your leaf to the correct column of the graph." I ask for questions and then call each day. I check that students know which day they need to put their leaf on and we build a graph using the leaf pictures.
"I would like you to look up here at our graph. Can you tell me on what day most people thought that their tree had mostly changed color?" (I ask other questions based on the graph's outcomes.)
I ask for comments about what students notice about the graph.
"We designed an experiment to answer our question. Thumbs up if you think we found an answer to whether leaves change color quickly or slowly. Did we all agree? Is it ok not to always agree about something? Did we talk about our differences? How many of you learned something from talking to your friends and looking at our graph today? Do you think you could design another study to answer a question you might have?"
I use the journals to assess student understanding of recording and analyzing data.