We describe an activity that introduces school-aged children to clinical trials, that presents the terminology associated with randomized controlled trials, and that reveals how the findings from clinical trials are applicable to everyone everywhere.

The contrary of stochastic independence splits up into two cases: pairs of events being favourable or being unfavourable. Examples show that both notions have quite unexpected properties, some of them being opposite to intuition. For example, transitivity does not hold. Stochastic dependence is also useful to explain cases of Simpson's paradox.