Lesson: The Scientific Method

The scientific method is a systematic process that scientists use to explore observations and answer questions. It's not a rigid checklist, but a logical framework that helps ensure that findings are based on evidence and sound reasoning. Select a step below to learn more.

1. Make an Observation

This is the starting point. You notice something in the world and become curious about it. It could be something you see, hear, or experience. An observation leads you to wonder "Why?" or "How?".

Example: You notice that your houseplant, which sits by a sunny window, has started to wilt and its leaves are turning yellow, even though you water it regularly.

2. Ask a Question

Based on your observation, you formulate a question that you want to investigate. A good scientific question is specific and can be tested.

Example Question: "Is my houseplant getting too much direct sunlight?"

3. Form a Hypothesis

A hypothesis is a potential answer to your question. It's a testable prediction, not just a random guess. It is often written in an "If..., then..." format to show a cause-and-effect relationship.

Example Hypothesis: "If I move the plant to a less sunny spot, then its leaves will stop yellowing and it will stop wilting."

Test Your Knowledge

Which of the following is the best hypothesis?

I think my plant is sad. If a plant gets less direct sunlight, then its health will improve. Why are my plant's leaves yellow?

4. Conduct an Experiment

This is where you test your hypothesis. An experiment should be a fair test where you change only one factor (the independent variable) and observe the effect on another factor (the dependent variable). All other conditions (controlled variables) should be kept the same.

Example Experiment: You move the wilting plant to a different room that gets indirect sunlight. You keep watering it the same amount and at the same time as before. You observe the plant for one week.

Independent Variable: Amount of sunlight.
Dependent Variable: The plant's health (leaf color, wilting).
Controlled Variables: Amount of water, type of soil, room temperature.

5. Analyze the Data

Once your experiment is complete, you collect your measurements (data) and analyze them to see what happened. This often involves making charts, graphs, or tables to see patterns in the information.

Example Analysis: After one week, you observe that the plant's leaves are no longer yellowing and the plant is standing upright (not wilting). You note these changes in a logbook.

6. Draw a Conclusion

Based on your analysis, you decide whether your hypothesis was supported or refuted (proven wrong). You state your conclusion and explain why you think it happened. Science is a continuous cycle; a conclusion often leads to new questions and new experiments.

Example Conclusion: "My hypothesis was supported. The plant's health improved when it was moved out of direct sunlight. Therefore, too much direct sunlight was causing the plant to wilt and its leaves to turn yellow."

Test Your Knowledge

What do you do in the conclusion step?

Design a new experiment. Ask a new question. State whether your hypothesis was supported by the evidence.

The cycle of science never ends. What new question could you ask about the plant now?