# Cartesian Diver Activity for Questioning Strategies

### Overview

An activity to practice questioning strategies to facilitate students construction of an explanation for what happens in this activity.

### Materials

• Plastic pop bottle (1 or 2 liter)
• Glass eye dropper
• Water
• Recorder
• Tape

### Procedure

• Get a recorder, video or audio tape to record the experiment and discussion.
• Get a group of people (age 10 and up).
• Have an "Eye Dropper" system ready for the people.

### Set up for the Dropper - Pop Bottle System.

1. Put enough water in the eye dropper so that it will just barely float. You may want to do this in a large container before placing the eye dropper into the plastic pop bottle.

2. Fill the plastic pop bottle with water.

3. Place the eye dropper into the pop bottle.

4. If the eye dropper does not float you will need to remove it and reduce the water in the eye dropper until it floats.

5. Put the lid on the pop bottle.

6. When you squeeze the pop bottle the eye dropper may sink. If the eye dropper does not sink then you need to remove the eye dropper and increase the amount of water in the eye dropper.

### Procedure for Interacting with Students

Let students explore the Eye Dropper system.

After 5-10 minutes ask questions about their observations. The purpose of the questioning is to help them construct possible causes of the interactions.

YOU ARE ONLY TO ASK QUESTIONS. Do not tell anything. Guide their observations with questions so they construct their own reasons for themselves.

Have people distinguish between observation and inference.

Possible questions:

• What happened?
• What did you observe?
• What observation gave you that inference (idea)?
• Do you agree with ______ (person or idea)? Why?
• Did you observe what ___ said?

Desperate questions:

• What happens to the eye dropper on the bottom?
• What happens to the eye dropper on the top?
• What is the difference?

Have students summarize what they believe happened. Could have them draw a picture or write a summary.

After students construct an explanation for the experiment. Ask them what is a variable? Ask, what are the variables in the system? Ask, what would happen if these variables were changed? Ask questions to get students to use their observations to support their answers. Help them to distinguish between observations and inferences if needed.

Listen to your recording and collect the data needed to complete the following.

1. Write two of the most open ended (divergent) questions you asked.

2. Time the total number of seconds for your number one wait-times (after you asked a question). Record the information below.

Number one wait times for each question

Average number one wait-times

3. Time the total number of seconds for your number two wait-times (after a student responded and before you responded or asked a question). Record the information below.

Number two wait times for each question

Average number two wait-time.

4. If you slipped and told the students some information what did you tell?

5. How many times did you repeat student’s answers?

6. If you used a student’s idea, write it.

7. Summarize what you learned.

8. What goals do you have for your questioning strategies and why?