Science is a systematic way of learning about the natural world. It helps us answer questions by gathering evidence, testing ideas, and revising our understanding when new evidence appears.
How scientific investigation works
- Ask a question. For example: Does a certain amount of sunlight affect how quickly a plant grows?
- Research what is already known. Previous studies can help you develop a testable idea.
- Make a hypothesis. A hypothesis is a proposed explanation or prediction, such as “Plants receiving more sunlight will grow faster.”
- Test the hypothesis. Design a fair investigation. Change one factor—such as sunlight—and keep other conditions, like water and soil, as similar as possible.
- Collect and analyze evidence. Record measurements and look for patterns, while considering possible errors or alternative explanations.
- Draw a conclusion and share it. Decide whether the results support the hypothesis, explain limitations, and make the findings available for others to assess.
What makes science reliable?
- Evidence: Scientific explanations need support from observations or measurements.
- Testing: Other people should be able to check how a result was reached and, where possible, repeat the investigation.
- Revision: Scientific knowledge can change when stronger evidence becomes available. Revising an explanation is a strength, not a failure.
- Uncertainty: Scientists distinguish between what is well established, what is likely, and what remains unknown.
Science does not answer every kind of question. It is especially useful for questions about how the natural world works; questions about values, meaning, or personal preferences may require other forms of reasoning as well.
In short: science is not simply a collection of facts. It is an evidence-based process for asking questions, testing explanations, and improving what we know.