How science works: evaluating evidence in biology and medicine

Do vitamin C and other antioxidants benefit health? Using observational and experimental studies to test medical hypotheses

Can police dogs identify criminal suspects by smell? Using experiments to test hypotheses about animal behavior

Why are frogs in trouble? Complementary observations and experiments to test hypotheses in ecology

How do animals find stored food? Strong inference by testing alternative hypotheses

What causes cancer? The complexities of causation

Why do we age? Different levels of causation as complementary explanations

How does coffee affect health? Combining results of multiple studies

How will climate change affect the spread of human diseases? Models and the perils of prediction

Conclusion : how science works and its role in society

Appendix 1 : Using data for twins to estimate genetic and environmental contributions to the risk of cancer

Appendix 2 : Precision and the power of statistical tests.