Scientific Method

1. Scientific Method

2. Steps in the Scientific Method • Problem/Question • Observation/Research • Hypothesis • Experiment • Collect & Analyze Data • Conclusion • Retest/Apply the results

3. Problem/Question • All good scientific inquiry begins with a problem or a question about a topic. • This problem can be solved through experimentation.

4. Observations • Gathered through your senses • A scientist notices something in their natural world • Often called research (learning about problem)

5. Observations • An exampleof an observation might be noticing that many salamanders near a pond have curved, not straight, tails

6. Hypothesis • A possible solution to the problem. • Must be testable • Often written as If…Then… statements • Based on relationship between independent and dependant variables.

7. Hypothesis • An example of a hypothesis might be: The salamanders have curved tails due to a pollutant in the moist soil where they live.

8. Experiment • A materials list is created • A detailed procedure is developed and followed. • Data is collected and measured

9. Analysis • Analyzeyour data and results, confirm by retesting. • Modify the procedure if needed.

10. Conclusion • Conclusion: includes a statement that either accepts or rejects the hypothesis. • As conclusion is written, include any data tables, charts, graphs and photographs

11. Conclusion • It is usually the answer to the hypothesis based on the data obtained from the experiment • If needed apply the answer to solve the problem.

12. Scientific Experiments Follow Rules • An experimenter changes one factor andobserves or measureswhat happens.

13. Important vocabulary

14. A Variable Variable – factor in the experiment that is being changed,watched, or manipulated. 3 types

15. The Control Variable • control variables – factors that are kept constant so that they do not effect the outcome. • NOT tested • Are use for comparison

16. Other Variables • The factor that is changed or manipulated is known as the independent variable. (iv) • The factor that is measured or observed is called the dependent variable. (it changes because of iv)

17. Example of Controls & Variables • For example, suppose you want to figure out the fastest route to walk home from school. • You will try several different routes and time how long it takes you to get home by each one. • Since you are only interested in finding a route that is fastest for you, you will do the walking yourself.

18. What are the Variables in Your Experiment? • Varying the route is the independent variable • The time it takes is the dependent variable • Keeping the same walker throughout makes the walker a control variable.

19. It is best to make several trials with each independent variable.

20. Valid Experiment • A valid experiment will only have ONE variable tested! • Is repeatable by anyone • Has detailed step by step procedure • Has precise materials list

21. Data • Results of the experiment • May be quantitative (numbers) or qualitative other types • Must be organized • into charts, tables, or graphs

22. Retest In order to verify the results, experiments must be retested.