The Scientific Method

Steps in the Scientific Method

• The scientific method involves observation, hypothesis, experiment, data collection, conclusion, and retest.
• The scientific method is used to solve problems by identifying a problem, making observations, forming a hypothesis, designing an experiment, collecting data, forming a conclusion, and retesting.

Observations

• Observations are gathered through our senses.
• A scientist notices something in their natural world that sparks their curiosity.
• An example of an observation is noticing that many salamanders near a pond have curved, not straight, tails.

Hypothesis

• A hypothesis is a suggested solution to the problem that must be testable.
• It is sometimes written as an If…Then… statement.
• A hypothesis predicts an outcome, for example, that the salamanders have curved tails due to a pollutant in the moist soil where they live.

Experiment

• An experiment is a procedure to test the hypothesis.
• A variable is a factor in the experiment that is being tested.
• A good or “valid” experiment will only have ONE variable.

Controls and Variables

• In an experiment, the experimenter changes one factor and observes or measures what happens.
• The control variable is the factor that is kept constant to prevent it from affecting the outcome.
• The independent variable is the factor that is changed, and the dependent variable is the factor that is measured or observed.
• Controls are used for comparison, and they are not being tested.

Example of Controls & Variables

• For example, in an experiment to find the fastest route to walk home from school, varying the route is the independent variable, and the time it takes is the dependent variable.
• Keeping the same walker throughout makes the walker a control variable.

Valid Experiments

• A valid experiment requires two groups: the control and experimental groups.
• There should be only one variable.

Data

• Data is the result of the experiment and may be quantitative (numbers) or qualitative.
• Data must be organized and can be organized into charts, tables, or graphs.

Conclusion

• The conclusion is the answer to the hypothesis based on the data obtained from the experiment.

Retest

• Experiments must be retested to verify the results.

Understand the steps involved in the scientific method, including observation, hypothesis, experiment, data collection, conclusion, and retest. Learn how the scientific method is used to solve problems.