What Science Is and How We Know Things
Science as a Way of Learning
What science means
Science is a careful way of learning about the natural world. It uses observation, questions, testing, and evidence to build reliable explanations. In science, ideas are not accepted because they sound good; they are accepted because they are supported by data.
Big idea
Science helps us answer questions like: What happens? Why does it happen? How can we test whether an answer is correct?
Observation and inference
An observation is something you notice with your senses or tools. An inference is a conclusion you draw from observations. For example, seeing wet ground is an observation; concluding that it rained is an inference.
Which of the following is an observation?
"The ground is wet" is something directly noticed, so it is an observation.
Correct answer: The ground is wet
In one sentence, what is science?
Science relies on evidence, testing, and observation to understand nature.
Correct answer: A careful way of learning about the natural world using evidence.
Models, hypotheses, and theories
Core terms
Hypothesis vs. theory
Hypothesis
- A starting explanation
- Can be tested quickly or over time
- May be supported or rejected
Theory
- Built from lots of evidence
- Explains many related facts
- Changes only when strong new evidence appears
Why are scientific models useful?
Models simplify reality so we can study it more easily.
Correct answer: They make complex ideas easier to study
A simple scientific method
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Step 1: Ask a question
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Step 2: Make a prediction
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Step 3: Test it with an experiment or observation
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Step 4: Collect and examine data
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Step 5: Draw a conclusion and revise if needed
Why is evidence important in science?
Scientific ideas must be supported by observations and tests.
Correct answer: Because evidence helps determine whether an explanation is reliable.