Structured Practice

Probability and screening tests

Descriptive Answer

Descriptive Answer 20 marks 35 minutes 500 words

A disease is rare but a test is highly accurate. Explain why many positive results may still be false positives using base-rate reasoning.

Practice workspace

Write notes or your response

35:00

Suggested approach

Define relevant concepts; show calculations where required; connect scientific mechanisms with policy implications; state assumptions.

Self-assessment rubric

Concept accuracy 35%; reasoning/calculation 30%; application 25%; clarity 10%.