Scientific Method and Hypothesis
Hypothesis and method
A scientific hypothesis is a testable, provisional explanation or prediction. The method typically includes observation, problem formulation, hypothesis, deduction of consequences, experiment or observation, and revision. Good hypotheses are empirical, falsifiable, precise, and fertile in predictions. Operational definitions specify how variables are measured.
Testing
A controlled experiment varies one factor while holding relevant conditions constant, often using a control group. Confirmation supports a hypothesis; it does not prove it conclusively. Auxiliary assumptions may be revised when predictions fail. A theory is a broad, well-supported explanatory framework, not merely a guess.
Worked example
Hypothesis: increased light increases plant growth. Operational definition: height in centimetres after four weeks. Prediction: plants given more light will grow taller under otherwise equal conditions. A controlled trial with equal soil, water, and temperature compares light levels. If the high-light group grows taller, the hypothesis is supported; if not, it is disconfirmed or the auxiliary assumptions are examined.
Traps that cost marks
- Treating unfalsifiable claims as scientific hypotheses.
- Confusing confirmation with proof.
- Changing the hypothesis ad hoc whenever evidence conflicts.
- Failing to control confounding variables.
- Calling a theory a mere opinion.
- Ignoring operational definitions and measurement error.