1. 1.1.2 Scientific Method

2. The Scientific Method
The Scientific Method involves the following steps:
Making observations
Formulating a hypothesis
Designing a controlled experiment
Collecting and interpreting data
Forming a conclusion
Comparing the conclusion with existing knowledge
Reporting and publishing the results
Developing theories and principles

3. Scientific Method 1.1 THE SCIENTIFIC METHOD (2 class periods)
Biologists seek solutions to problems that relate to the living world and employ processes of science that lead to the discovery of new knowledge.
The process of science can be termed the scientific method.
Even though the scientific method is quiet variable, it is possible to point out certain steps that characterise the scientific method:
Making observations
Formulating hypotheses to explain the observations
Testing the validity of the hypotheses by designing a controlled experiment
Collecting and interpreting the data from the experiment
Coming to a conclusion
Placement of conclusions in the context of existing knowledge
Reporting and publishing results
Which may lead to the formation of theory and scientific principle
The observations ,hypotheses and experiments are documented in accessible sources where all can examine them. These results are expected to be repeatable, that is, to be obtained by anyone following the same procedure.
It is the aim of enquiry to formulate theories and principles to explain the existence, development and functions of the natural world.
The scientific method may be used in areas that raise ethical issues. In recent years such contentious issues have been mainly related to the origin of life, human reproduction, medicine and developments in biotechnology

4. The Edward Jenner Story

5. e.g. Edward Jenner’s investigation
The Scientific method
e.g. Edward Jenner’s investigation
Jenner noticed that people who caught Cowpox (a minor disease) did not seem to get Smallpox (a fatal disease).
Jenner hypothesised that if someone got cowpox and recovered then they would not get smallpox.
The Scientist
makes an Observation
A hypothesis
is formed. (A hypothesis is an educated guess based on the initial observation).

6. An experiment is designed to test the hypothesis.
4. Interpretation of results.
5. Conclusion
Jenner injected a boy with cowpox and later injected him with smallpox. Jenner tested the boy for smallpox and found that he did not have it. Jenner concluded that a person who once had cowpox would not get smallpox.

7. Based on the results of an experiment a hypothesis can be supported, rejected or changed and retested.
Details of the experiment and the results can be published in a Journal to inform the scientific community and allow further research.
If a hypothesis is continually supported by many experiments it becomes known as a theory.
When a theory has been shown to be correct under all conditions then it becomes known as a Law or Principle.

8. Observation
You observe something using your senses or machines which are basically extensions of those senses.

9. Question You ask a question about what you observed.
Form a question about a specific event or reaction
State it as a problem or question.
E.g. How does human activity affect global warming?
Why are honeybee populations suddenly declining in North America?
What enables birds to migrate such long distances? How do black holes form?

10. Design an Experiment
Devise a way to test whether your hypothesis is correct or not.
Create a controlled experiment.
A controlled experiment MUST have 2 groups.
The outcome must be measurable.
Record and analyze data.

11. Collect & Analyze Data
You do the experiment(s) using the method you came up with and record the results.
You repeat the experiment to confirm your results.

12. Two Types of Data
QUANTITATIVE: numerical data, deals with specific quantities, usually in the form of a graph or chart
QUALITATIVE: descriptive data, describes how something looks, smells, sounds, or feels; deals with qualities

13. Learning check
What is the next step?
The Conclusion

14. Draw Conclusions
Determine from the data collected if the hypothesis was correct or incorrect
Try to explain your results.

15. Compare
You compare your conclusion with existing
knowledge.

16. Finally You Report and Publish your results.
You Develop a theory or principle.

17. Progression of Ideas in Science
Hypothesis- a possible explanation to a question based on information the scientist has already gathered
If experiments show a hypothesis to be correct, other scientists may accept it as support for a scientific theory.
Eg: Plants obtain their energy from the sun.

18. Scientific Theory - a general statement of why things work based on hypotheses that have been tested many times
Scientific Law - a statement of what happens in a certain event based on verified observations & experiments

19. Progression of Ideas in Science
Which one is most likely to be wrong- hypothesis, theory, or law? 1. 2. 3.
Hypothesis
Theory
Law

20. What are the main steps in the Scientific Method?
Observation
Hypothesis
Experiment
Result
Conclusion

22. Steps in the scientific method
Observation
Question
Hypothesis
Test/Experiment
Results
Conclusions

23. Limitations of the Scientific Method

24. Limitations of the Scientific Method
Is limited by the extent of our basic knowledge
is limited to what can be observed with the five senses
tells us “how” a process works, not “why” e.g., does not really explain why the Universe exists
may be affected by the emotional involvement of investigator
may be affected by time pressure for results

25. Limitations of the Scientific Method
limitations of our measurement instruments
ethical and legal responsibilities
religious beliefs
we can never be sure all untested variables are controlled
scientists sometimes make mistakes

26. Song on Scientific Method

27. END

28. Websites of Interest

29. Expt to demo the scientific method