Nature and Impact of Science and Engineering
What the exam tests
This domain asks you to reason about how scientific knowledge is built and how engineering solves problems, not to recite vocabulary. Know the scientific method as a flexible cycle: observation, question, hypothesis, prediction, controlled experiment, analysis, revision. Distinguish a hypothesis (a testable, falsifiable prediction) from a theory (a well-supported explanatory framework built from many lines of evidence) and a law (a concise description of a consistent pattern). A common trap is the everyday use of "theory" as a guess; on the exam, theory signals strength of evidence.
Experimental design
Identify the independent variable (what the researcher manipulates), the dependent variable (what is measured), and controlled variables (conditions held constant). A control group receives no treatment or a placebo. Watch for items asking whether an experiment supports a causal claim: random assignment plus a control group supports causation, while correlation alone does not.
Engineering and society
The engineering design cycle (define the problem, research, prototype, test, iterate) parallels but is not identical to the scientific method; engineering is judged by criteria and constraints, science by explanatory power. Be ready to discuss peer review, reproducibility, bias, funding influences, and ethical trade-offs in technology.
Rule of thumb
If a question asks what would strengthen a conclusion, look for replication, larger samples, or tighter controls, not merely a bigger effect size.