Physical Science / Unit 1: Science Skills and Measurement
1.1 The Scientific Method
Notes
The scientific method is a flexible set of steps scientists use to answer questions with evidence.
- Typical steps: ask a question, research, form a hypothesis, test it with an experiment, analyze the data, draw a conclusion, share results.
- A hypothesis is a testable, falsifiable prediction, often written "If ..., then ...".
- The independent variable is what you change on purpose. The dependent variable is what you measure. Controlled variables are kept the same.
- A control group gets no treatment so you can compare it with the test group.
- Example: To test whether sunlight affects plant growth, light is the independent variable and plant height is the dependent variable.
Practice
Which statement is a testable hypothesis?
A hypothesis is a prediction that an experiment can support or refute.
A student tests how the temperature of water affects how fast sugar dissolves. What is the dependent variable?
The dependent variable is the result you measure, here the dissolving time.
Why do scientists include a control group in an experiment?
The control group shows what happens without the treatment.
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