1. CHAPTER 1 SECTION 3: METHODS OF SCIENCE
Ms Su’ad

2. Scientific methods
Biologists work across the globe trying to find answers to their questions. No matter where they work, all biologists use the scientific method to gather information and answer questions.

3. Scientific methods
Observations – gathering information about something.
Ex. Taking a picture, describing the way something smells or looks
Inferences – a conclusion you make about something based on what you know and what you have learned.
Ex. ‘The teacher can infer that students who pay attention in class are more likely to succeed.’
Hypothesis – a testable explanation of a situation.
Ex. ‘Eating a hamburger every day for a month will cause your cholesterol level to rise’.
Experiment – a test in a controlled setting
Ex. Conduct an experiment where someone eats a hamburger every day for a month and record their cholesterol levels before and after.

4. Scientific methods
Control group – the experiment or group used for comparison.
Ex. Group of people who did not eat a hamburger for a month.
Experimental group – the group that is exposed to the factor being tested.
Ex. Group of people that is eating the hamburger.
Independent variable – the one factor that can change because it is the factor that’s being tested.
Ex. Cholesterol levels
Dependent variable – the factor that changes because of the independent variable.
Ex. Weight (or anything else that changes)

5. Scientific methods
Constant – the factor that remains the same during an experiment.
Ex. The hamburger
Biologists gather their data and analyze the results using the metric system, graphs, and computers.
Biologists report their findings and conclusions in scientific journals to share with other scientists.

6. Question?