What are Variables in science and how are they used? Ms. Fox Science 6

Learning Goal: We can identify, define and describe the three types of variables in every good science experiment.   1   2 3 4 Independent Variable and Dependent Variable?!? You may as well be speaking in Japanese! And what is it exactly I am supposed to control? Please slow down and explain this in another way. I can identify the variables but sometimes mix up the independent and dependent variables in an experiment. I pretty much understand that only one change can occur during an experiment but can use a little more practice. I understand the difference between independent and dependent variables and can identify each in an experiment. I understand which variable is the change and which has an effect. I can identify specific things in an experiment that must remain constant. I understand the difference between an independent and dependent variable and can identify each in an experiment. I can identify and explain the control variable and what remains constant. Not only that, I observe and analyze variables during an experiment and find ways to better control them in the future.

What three components that are in every good science experiment? Mark all that apply: Dependent Variable Control Variable Slime Explosions Independent Variable Dangerous Chemicals

Variables in an Experiment In your science notebooks, analyze the word VARIABLE What is the root word? What does it mean? What is the suffix? What does it mean? How do these meanings help us understand the word variable? What is the root word of, ”DEPENDENT?” What does the prefix “in,” mean in the word, “INDEPENDENT?”

Independent variable Discuss the graph below with your table group and identify the independent variable The independent variable (IV) is the one variable you change. It is the “cause” in “Cause and Effect” In a hypothesis, it is the “IF” statement: “If INDEPENDENT VARIABLE/CHANGE, then DEPENDENT VARIABLE/EFFECT (will increase, decrease, etc) because ___________. To find the IV, ask, what am I changing?

Dependent variable The dependent variable (DV) is the measurable effect that occurs because of the IV/change. It is like the “effect” in “Cause and Effect” To find the DV, ask what am I measuring? Or, what did my hypothesis say will happen? In a hypothesis, it is the “THEN” statement: “If INDEPENDENT VARIABLE/CHANGE, then DEPENDENT VARIABLE/EFFECT (will increase, decrease, etc) because… ___________. Discuss the graph below with your table group and identify the dependent variable

HYPOTHESIS In science, a hypothesis IS an idea or possible explanation that can be tested through study and experimentation. A good hypothesis is based on direct observation and research. A hypothesis IS NOT a guess. It is based on evidence but it does not have the credibility of a scientific theory. Guess < Hypothesis < Scientific Theory

Use the question to write a hypothesis, then identify the variables Will paper airplanes with more weight fly in a straighter path than lighter planes? Hypothesis (use If_____, then_________, because______.) Independent Variable Dependent Variable How can it be measured?

Practice Complete the worksheet on variables. You may discuss these with your group members to help clarify.

Think about this… Let’s say that Brad has a pimple. He wonders what will get rid of it. He’s heard that putting toothpaste on the zit will get rid of it. He’s also heard that lemon juice will get rid of it. He decides to rub his face with lemon juice and toothpaste. The next morning his pimple is gone. But which thing cured him? The toothpaste or the lemon juice? Do you think it was the toothpaste? Do you think it was the lemon juice? Are you unsure? Talk it over with your groups. Be prepared to share about your discussions.