Process of the Scientific Method

The Scientific Method The scientific method is a way to solve a problem This is the method on which all projects should be based.

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

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

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

Question You ask a question about what you observed. State it as a problem or question.

Learning check What are the steps in the Scientific Method?

Hypothesis Hypothesis: a testable‚ tentative answer to a question    You predict what you think the answer to your question might be.The hypothesis is a testable explanation for what was observed. The scientist tries to explain what caused what was observed.

Experiment You figure out a way to test whether your hypothesis is correct or not. The outcome must be measurable. (quantifiable) Record and analyze data.

Result You do the experiment(s) using the method you came up with and record the results. You repeat the experiment to confirm your results.

Learning check What is the next step? The Conclusion

Conclusion You state whether your prediction was confirmed or not and try to explain your results.

Compare You compare your conclusion with existing knowledge.

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

Need to know State the process of the Scientific Method Explain the following: Observation, ■ Hypothesis, Design Experiment, Record & Analyze Data, Conclusions, Compare to Existing Knowledge, Reporting, ■ Theory ■ Principle

Limitations of the Scientific Method

Limitations of the Scientific Method Is limited by the extent of our basic knowledge Is limited by our ability to interpret the results is limited to what can be observed with the five senses e.g., what existed prior to the Big Bang and the known universe is outside of the realm of science to investigate is limited to the present tells us “how” a process works, not “why” e.g., does not really explain why the Universe exists

Limitations of the Scientific Method may be affected by the emotional involvement of investigator may be affected by time pressure for results ethical and legal responsibilities Religious beliefs we can never be sure all untested variables are controlled

Need to know State the limitations of value of the Scientific Method

1.1.3 Experimentation

(Hint: I change the Independent variable) What is an experiment? 1. An experiment is a controlled test. 2. Only one variable should be changed at a time. a. Independent variable – changed by the experimenter. (Hint: I change the Independent variable) b. Dependent variable (Responding) – the effect.

What is an experiment? 3. Constants do not change. 4. Controlled variables are those which could change, but are not allowed to. 5. Two parts to an experiment: a. Control group – normal conditions. b. Experimental group(s) – variables are changed. 6. Prediction is the goal of experiments.

How to organise an experiment OR The Principles of Experimentation Plan and design the experiment Be aware of Safety procedures Select organisms at random Use a large enough sample size Use a control group Use Double-blind testing Change one factor at a time Measure changes Analyze the results State possible sources of error Repeat the experiment

Learning check What is an experiment? It is a controlled test where only one variable is changed at a time.

An example of an experiment Observation: It has been suggested that large daily doses of Vitamin C protect against the common cold virus. Hypothesis: Vitamin C protects against the common cold virus

An example of an experiment Experiment design: Ten adult males in their mid twenties who are friends of the investigator were chosen to test the possible value of vitamin C. 5 of them were given 3000mg of vitamin C a day; the other 5 were given a placebo. Which is the control group? Which is the experimental group? Is this a good experiment?

Problems with experiment design All males All mid twenties All friends Not a large enough sample

A Good Experiment Should Have only one variable Use a large number of samples Use random selection Be repeated Use double blind testing

Learning objectives Random Selection Planning & Design Replicaton Can you state about eight principles of experimentation? Random Selection Replicaton Double-Blind Testing Sources of errors Planning & Design Safety Procedure Control Experiment Sample Size

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