Science, Engineering, and Technology
Key concepts
This domain tests how scientific knowledge is built and how engineering solves problems. Know the scientific method as a flexible cycle: observe, question, research, hypothesize, experiment, analyze data, and communicate. A hypothesis must be testable and falsifiable; a prediction is a specific expected outcome. Identify the independent variable (what the experimenter changes), dependent variable (measured response), controlled variables (held constant), and control group (baseline for comparison). Engineering design involves defining a problem, specifying criteria and constraints, brainstorming, prototyping, testing, and iterating; trade-offs are expected. Technology is any human-made system or tool that meets a need, not only digital devices. Data literacy matters: choose appropriate graphs, recognize outliers, distinguish accuracy from precision, and separate correlation from causation. Peer review and replication strengthen claims; a scientific theory is a well-supported explanation, not a guess.
Traps: questions often swap independent and dependent variables, call a constant a control, or imply one experiment proves a theory. “Proof” is rare in science; evidence supports or refutes hypotheses. A law describes a consistent relationship, while a theory explains it. Correlation does not establish causation. Precision is repeatability; accuracy is closeness to the true value.
Worked example: Students test whether fertilizer affects plant height. Amount of fertilizer is the independent variable; final height is the dependent variable; same pot size, soil, water, and light are controlled variables; a no-fertilizer group is the control. Rule of thumb: change one variable at a time, measure the response, and compare against a baseline.
Rule of thumb: if a claim cannot be tested or potentially shown false, it is not a scientific hypothesis.