Nature of Science
What the test calls "science"
Science is a process, not a collection of facts. A hypothesis is a testable, falsifiable prediction; a theory is a broad explanation supported by many lines of evidence (not a guess); a law describes a consistent relationship, often mathematically. Questions often test whether you can tell these apart - the trap is choosing "theory" as a synonym for "unproven idea."
Designing and reading experiments
Identify the independent variable (what the researcher changes), the dependent variable (what is measured), and controlled variables/constants (held fixed). The control group receives no treatment or a placebo and provides a baseline; it is not the same as a controlled variable. Strong designs use replication, adequate sample size, randomization, and blinding to improve reliability (consistency) and validity (measuring what you claim). Distinguish observation (directly sensed) from inference (interpretation), and correlation from causation.
Data and communication
Quantitative data are numerical; qualitative data are descriptive. Match graphs to data type (bar for categories, line for continuous change). Results are shared through peer review, which screens for flaws but does not guarantee truth. Models are simplified representations with limits.
Worked example
A student waters plants with 0, 5, and 10 g of fertilizer and measures height after four weeks. Independent variable: fertilizer amount. Dependent variable: height. Constants: light, water volume, soil, pot size. Control group: the 0 g group. Rule of thumb: if a claim cannot be tested in a way that could prove it wrong, it is not a scientific hypothesis.