A scientist tries to determine why a particular car is getting a much lower gas mileage than claimed by the manufacturer by systematically designing experiments to test possible causes for the problem. This is an example of

• A. observational science
• B. hypothesis-driven science
• C. descriptive science
• D. theoretical science

Answer: (B)

Testing possible causes with controlled experiments is hypothesis-driven science. In this approach, the scientist isn’t just watching or describing what happens; they propose specific explanations for the low gas mileage and design experiments to see whether those explanations hold up under controlled conditions. By manipulating one factor at a time—such as tire pressure, maintenance status, driving style, or fuel type—while keeping other variables constant, they can observe whether the mileage responds in ways that support or refute each hypothesis. If changing a factor consistently changes mileage as predicted, that factor becomes a likely contributor. If mileage remains unchanged despite a manipulation, that factor is unlikely to be the cause. This method contrasts with observational science, which gathers data without testing specific causes, and with descriptive or theoretical science, which focuses more on describing phenomena or building models rather than conducting targeted experiments to test explanations.