Foundations of Scientific Inquiry and Earth Science Practices
Domain 1 focuses on how Earth scientists build and test explanations: observation, hypothesis, variables, controls, measurement, models, maps, and uncertainty. Expect items that ask you to evaluate an investigation rather than recall a definition.
Core rules and concepts
- A hypothesis must be testable and falsifiable; a theory is a well-supported explanatory framework, not a guess.
- Identify independent, dependent, and controlled variables; replication and random assignment reduce bias.
- Use SI units and convert carefully: 1 km = 1,000 m; 1 cm³ = 1 mL; density = mass/volume.
- Precision is repeatability; accuracy is closeness to the true value. Report uncertainty and significant figures consistent with the instrument.
- Topographic maps show elevation with contours; closer contours mean steeper slope. Scale converts map distance to ground distance.
- Models and remote sensing extend observation but carry assumptions and resolution limits.
Worked example
A stream channel is 4.0 m wide, averages 0.50 m deep, and water moves 0.80 m/s. Discharge Q = width × depth × velocity = 4.0 × 0.50 × 0.80 = 1.6 m³/s. The units work because m × m × m/s = m³/s. If the reported width were 4 m rather than 4.0 m, significant figures would limit the answer; the reasoning, not just the number, earns credit.
Traps that cost marks
Do not confuse correlation with causation. Do not call a controlled experiment proven. Watch map scales and unit conversions, and do not treat precision as accuracy. A model’s output is only as good as its assumptions and input data.