Scientific Literacy and Application
Scientific literacy and application tests whether you can use evidence, interpret data and apply science to everyday decisions. Questions may give a short claim, a table or a graph and ask you to identify variables, judge reliability, or explain a technological choice.
Core rules and concepts
- A hypothesis is a testable prediction, not a guess stated as fact.
- The independent variable is changed; the dependent variable is measured; controlled variables are kept constant.
- A single trial is weak evidence; repeat and use a suitable sample.
- Correlation does not prove causation.
- Read graphs by naming the axes, noting units, and describing the trend before drawing a conclusion.
- Distinguish precision (repeatability) from accuracy (closeness to the true value).
- Applications should be justified with a scientific property, for example copper for wires because it conducts well.
Worked example
A student claims detergent A is better because it makes more foam. The test uses 1 L of water, the same temperature and the same amount of cloth, but different amounts of detergent. Foam height is measured. The independent variable is the detergent type, the dependent variable is foam height, and the controlled variables are water volume, temperature and cloth. Because detergent amount differs, the comparison is unfair. A valid conclusion needs equal detergent concentrations and repeated trials. Also, foam is not a direct measure of cleaning power.
Traps that cost marks
- Treating a correlation as proof of cause.
- Ignoring sample size or repeats.
- Confusing precision with accuracy.
- Mixing units or failing to convert them.
- Accepting an advertisement's claim without a controlled test.