1. Scientific Method

2. The Nature of Science
The goal of science is to understand the world around us.

4. The Scientific Method
Scientists gather information and study a problem by following a logical set of steps - the scientific method.

5. The Scientific Method
There are different scientific methods to solve problems. Here is a well established method.
Observe and state the problem

6. 3. Do background research

7. 3. Form a hypothesis a statement that can be tested
written as an “If… then…” statement

8. 4. Test the hypothesis

9. 5. Record and analyze data

11. 6. Form a conclusion

12. 7. Replicate the work

14. The Scientific Method
Scientist gather information and study a problem by following a logical set of steps - the scientific method.
There are different scientific methods to solve problems. Here is a well established method.
Observe and state the problem
Do background research
Form a hypothesis - a statement that can be tested
Test the hypothesis
Record and analyze data
Form a conclusion
Replicate the work

15. A Controlled Experiment
The hypothesis is a possible answer to problem that has been defined. The experiment (the test) must test only the condition that varies in the hypothesis. This condition is the variable.
This is s controlled experiment.

16. Designing Controlled Experiments
The researchers selected similar plots of marsh grass. All plots had similar plant density, soil type, input of freshwater, and height above average tide level. The plots were divided into control and experimental groups.

17. Designing Controlled Experiments
The researchers added nitrogen fertilizer (the independent variable) to the experimental plots. They then observed the growth of marsh grass (the dependent variable) in both experimental and control plots.

18. Scientist use 2 identical groups of subjects
Scientist use 2 identical groups of subjects. The group that is exposed the variable is the experimental group. The other is the control group. Experiments must be designed so other scientists can repeat them.

21. A theory is a hypothesis that has been tested and confirmed
A theory is a hypothesis that has been tested and confirmed. A theory makes predictions.