The Basic Method

1. The Basic Method

2. A scientific process • Data: supporting evidence • We all started going through the process of the scientific method as children. For example, we all learned that bouncing balls harder will make them bounce back up higher. • Here is the process that we went through: • Ask Question: “what will happen if I throw the ball down to the ground?” • Research: you observed other kids throwing balls and saw that their ball bounced back..you then wondered…”does this bouncing thing work for my ball.”

3. Con’t • You threw the ball down to the ground and found out that it did bounce. This lead to more questions. “What happens if I throw the ball harder?” This lead you to a hypothesis. • Hypothesis: a statement that predicts the relationships between two variables in an experiment. • Your hypothesis was the ball should go higher when I throw the ball harder toward the ground. • You then tested your hypothesis by throwing the ball harder.

4. Con’t • To put it another way, you found one thing that you were going to change (the downward force you were going to apply to the ball) and another thing you thought might change as a result of changing the first thing (the height of the bounce). • Scientists call the thing we change on purpose the independent variable. Independent variable: changed by the scientist not as a result of the experiment. In our example the independent variable was how hard the ball was thrown to the floor. • As a result of changing the independent variable, other variables in the experiment will change or respond. Dependent variables: change in response to the independent variable. In our example, the dependent variable was how high the ball then bounced due to how hard the ball was thrown.

5. Hypothesis: A cause and effect relationship • A hypothesis should be stated as a cause and effect statement. For example, if I place increasing amounts of downward force on a ball, then the resulting height will also increase. • This allows you to identify the independent and dependent variables easier. The “if” part of the statement is the independent variable and the “then” is the dependent variable.

6. Controlling Variables • How do I know the only possible cause of the ball bouncing higher is the increase in force I put on the ball? You have to only change one thing in the experiment. The things that you do not change are called the control variables. Control variables: the scientist does not allow these things to change during the experiment. • They are very important because they allow you to rule out other possible explanations for your experiment.

7. Conclusions • While you were throwing your ball, you were making some mental notes about how high the ball bounced. You came to the conclusion that your hypothesis was supported by the data. • Even if your hypothesis was not supported by the data…your experiment would not be a failure. You would still gain valuable information from it.

8. Scientific Method (Process)

9. Scientific Method Con’t • It’s important to understand that not all scientific processes will happen in exactly that order, but it does need to be orderly and consistent. Operationally: an orderly process used to solve a problem. • Doing the steps in order is also called completing the steps in chronological order. Chronological order: ordered by time, or going in order from beginning to end.