Nature of Science and Scientific Inquiry
The Nature of Science and Scientific Inquiry domain tests how well you can design, critique, and interpret investigations rather than simply recall facts. Expect items on hypothesis formation, variable control, measurement uncertainty, data representation, and the social processes - peer review, replication, ethics - that make a claim scientific.
Core distinctions
- Hypothesis, theory, law. A hypothesis is a testable, falsifiable prediction; a theory is a broad, well-supported explanatory framework (kinetic-molecular theory); a law is a compact description of a regularity (Coulomb's law). A law is not a "proven theory," and theories are never promoted into laws.
- Variables. The independent variable is manipulated; the dependent variable is measured; controlled variables are held constant. A valid experiment isolates one independent variable, and a control group establishes a baseline.
- Accuracy vs. precision. Accuracy is closeness to the accepted value; precision is repeatability. Random error scatters results and lowers precision; systematic error shifts every result the same way, destroying accuracy while leaving precision intact.
Worked example
A student measures g five times and gets 9.52 m/s²; the accepted value is 9.81 m/s². Percent error = |9.52 − 9.81| / 9.81 × 100 = 0.29/9.81 × 100 ≈ 3.0%. Because all five trials clustered within 0.02 m/s² of one another, the data are precise but inaccurate - the signature of a systematic error such as a mis-set timer or neglected air resistance, not careless technique.
Traps that cost marks
- Reporting a percent error with more digits than the inputs justify.
- Claiming a hypothesis is "proven" - evidence supports or fails to support it.
- Confusing the control group with a controlled variable.
- Forgetting that adding or subtracting keeps decimal places, while multiplying or dividing keeps significant figures.